Protein / target
Aromatase
Protein at a glance
Biological role
Estrogen 2-hydroxylase
Strongest disease association
Aromatase deficiency
Therapeutic position
Established drug target
Derived from structured UniProt, Open Targets and literature data on this page.
Protein profile
Canonical identity and biological annotation from UniProt.
Function overview
A cytochrome P450 monooxygenase that catalyzes the conversion of C19 androgens, androst-4-ene-3,17-dione (androstenedione) and testosterone to the C18 estrogens, estrone and estradiol, respectively.
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A cytochrome P450 monooxygenase that catalyzes the conversion of C19 androgens, androst-4-ene-3,17-dione (androstenedione) and testosterone to the C18 estrogens, estrone and estradiol, respectively (PubMed:27702664, PubMed:2848247). Catalyzes three successive oxidations of C19 androgens: two conventional oxidations at C19 yielding 19-hydroxy and 19-oxo/19-aldehyde derivatives, followed by a third oxidative aromatization step that involves C1-beta hydrogen abstraction combined with cleavage of the C10-C19 bond to yield a phenolic A ring and formic acid (PubMed:20385561). Alternatively, the third oxidative reaction yields a 19-norsteroid and formic acid. Converts dihydrotestosterone to delta1,10-dehydro 19-nordihydrotestosterone and may play a role in homeostasis of this potent androgen (PubMed:22773874). Also displays 2-hydroxylase activity toward estrone (PubMed:22773874). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (CPR; NADPH-ferrihemoprotein reductase) (PubMed:20385561, PubMed:22773874)
Subcellular location
Domains and Gene Ontology detail (19)Hide
Gene Ontology
- Cendoplasmic reticulum
- Cendoplasmic reticulum membrane
- Cmembrane
- Faromatase activity
- Felectron transfer activity
- Festrogen 2-hydroxylase activity
- Fheme binding
- Firon ion binding
- Foxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen
- Foxygen binding
- Fsteroid hydroxylase activity
- Pandrogen catabolic process
Biological roles
What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.
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Lipid & lipoprotein metabolism
- ·sterol metabolic process
- ·Endogenous sterols
View underlying pathways (3)Hide underlying pathways
Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.
Interaction neighbourhood
Proteins with the strongest functional or physical association. Node size and line weight reflect STRING confidence; hover or select a partner to inspect one association.
Functional and physical associations from STRING v12.0. Only associations with this protein are drawn — partner-to-partner links are not part of this evidence.
Approved medicines with mapped indications
Approved therapies targeting this protein, grouped by what they are approved to treat — the disease-first view of the medicines below. Relationships come from the canonical approved-indication graph (ChEMBL phase-4), the same source as the drug cards.
Broader indication categories (1)Hide
Broad umbrella indications (e.g. “Neoplasms”). Shown here because every medicine also appears under a more specific disease above — kept for completeness, de-emphasised for clarity.
6 medicines meet Open Targets' target-level approved-medicine definition; the 3 shown here are those on this page with a canonical approved disease indication in the graph. Approved indications from ChEMBL (phase-4), via the canonical drug→disease graph.
Drugs targeting this protein
How approved and investigational drugs engage this protein — mechanism and action type, direct vs complex targeting, and how broadly each acts across other targets. A drug-first view (the section above groups the approved ones disease-first); direct binders with few recorded targets are listed first.
Cytochrome P450 19A1 inhibitor
Indicated for Breast Neoplasms, Neoplasms
Cytochrome P450 19A1 inhibitor
Indicated for Breast Neoplasms, Neoplasms
Cytochrome P450 19A1 inhibitor
Indicated for Breast Neoplasms, Neoplasms
ChEMBL mechanism, action type, target identity and approved indications. Open Targets clinical status.
Translational evidence
Why this target matters therapeutically, strongest evidence first. Disease associations are gene-level (via the gene that encodes this protein) and open into the full confidence synthesis; the development universe, tractability and safety annotations are target-level, from Open Targets.
Strongest disease associations · via encoding gene CYP19A1
Gene-level evidence surfaced through the gene CYP19A1 that encodes this protein — not a direct protein–disease relationship. Ranked by Forefront's causal-directness weighting, so genetically- and clinically-evidenced diseases lead over ones that merely share the literature.
View evidence synthesis (5)Hide
The evidence agreement range shows how closely the independent evidence families agree — it is not a statistical confidence interval, and nothing here is fitted to outcome data. Derived from Open Targets evidence types under Forefront weighting; the per-type scores above show the calculation.
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Drug development
6 compounds recorded · 6 approved
View all recorded compounds (6)Hide
Open Targets known-drugs universe. Drug name and highest clinical stage only — the disease relationship is NOT read from this slice (it carries trial-context noise); approved indications come from the canonical graph above.
Tractability
Small molecules — Strong
Antibodies — Emerging
Protein degraders — Emerging
View underlying tractability evidence (6)Hide
Raw Open Targets tractability assessment buckets, by modality.
Safety-related annotations
Terms indexed against this target in Open Targets' safety data, with their datasource. These are annotations, not causal claims: the direction of effect (whether activation or inhibition is implicated), species and evidence strength are not captured here, so an entry does not mean that modulating this target is known to cause that condition.
Clinical trials
Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein. Ranked by active status, then clinical phase and recency, and spread across the targeting drugs.
View all trials (26)Hide
ClinicalTrials.gov via the drug-target graph.
What's happening now
Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for 3 drugs that target this protein, plus publications where such a drug is a genuine subject. Every item is reached indirectly through the drug, not the protein itself; incidental mentions (a paper that merely measures a drug) and press items are excluded.
- Trial status changed
Phase 2 Study of Neoadjuvant Endocrine Therapy in ER-positive, HER2-negative Early Stage Breast Cancer
- Trial status changed
Comparison of Rate of Complete Abortion Between Letrozole Plus Misoprostol vs Misoprostol Alone in First Trimester Pregnancy
- Trial status changed
A Phase 3 Randomized, Open-Label Study of OP-1250 Monotherapy vs Standard of Care for the Treatment of ER+, HER2- Advanced or Metastatic Breast Cancer Following Endocrine and CDK 4/6 Inhibitor Therapy (OPERA-01)
- Trial status changed
A Randomized, Open-label, Phase III Study of SIM0270 Combined With Everolimus Versus Treatment of Physician's Choice in Patients With CDK4/6 Inhibitors Previously Treated , ER+/HER2- Locally Advanced or Metastatic Breast Cancer
- Trial results posted
A Phase II, Single-Arm Study of RAD001 (Everolimus), Letrozole, and Metformin in Patients With Advanced or Recurrent Endometrial Carcinoma
- Trial status changed
A Phase II, Single-Arm Study of RAD001 (Everolimus), Letrozole, and Metformin in Patients With Advanced or Recurrent Endometrial Carcinoma
- Trial results posted
A Phase II Clinical Trial Evaluating the Combination of Onapristone With Anastrozole for Women With Refractory Hormone Receptor Positive Endometrial Cancer
- Trial status changed
A Phase II Clinical Trial Evaluating the Combination of Onapristone With Anastrozole for Women With Refractory Hormone Receptor Positive Endometrial Cancer
- New publicationAbemaciclib plus a nonsteroidal aromatase inhibitor as initial therapy for HR+, HER2- advanced breast cancer: final overall survival results of MONARCH 3.
- New publicationEfficacy, safety, and biomarker analysis of nivolumab in combination with abemaciclib plus endocrine therapy in patients with HR-positive HER2-negative metastatic breast cancer: a phase II study (WJOG11418B NEWFLAME trial).
- New publicationPalbociclib and Letrozole in Advanced Breast Cancer.
- New publicationRibociclib as First-Line Therapy for HR-Positive, Advanced Breast Cancer.
Objective event titles are shown unmodified; the event kind and significance line are derived from structured fields. Forefront AttentionEvent stream aggregating Europe PMC Regulatory filings ClinicalTrials.gov.