# TPH2

Source: https://onco.cc/targets/tph2/  
OnCo record `tph2` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

TPH2 (Tryptophan 5-hydroxylase 2) is an enzyme. The public catalogues list it as a drug target, and an approved or late-stage drug is recorded against it. Tied to Neuroendocrine tumours.

## Summary

Neuron-specific enzyme that catalyses the conversion of L-tryptophan into 5-hydroxy-L-tryptophan, the rate-limiting step in serotonin production, using Fe(2+) as cofactor and molecular oxygen and tetrahydrobiopterin (BH4) as cosubstrates. Plays a crucial role in regulating mood, anxiety and sleep.

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: tryptophan hydroxylase 2; Tryptophan 5-hydroxylase 2; FLJ37295
- Tags: cancer-genes-wave
- Symbol: TPH2
- Class: enzyme
- Biology: Neuron-specific enzyme that catalyses the conversion of L-tryptophan into 5-hydroxy-L-tryptophan, the rate-limiting step in serotonin production, using Fe(2+) as cofactor and molecular oxygen and tetrahydrobiopterin (BH4) as cosubstrates. Plays a crucial role in regulating mood, anxiety and sleep. Locus 12q21.1 (HGNC).
- Where found: Neuroendocrine tumours: Open Targets association 0.53 with neuroendocrine neoplasm (MONDO_0019496)

## Notes

- Written by scripts/fetch-cancer-genes.ts from CIViC, Open Targets, IntOGen, HGNC and UniProt; the function text is UniProt's, condensed and in UK spelling. Roles: Open Targets known-drug datatype score 0.86. Evidence tier "approved-drug" is the strongest of those signals.
- Prevalence not recorded: none of the sources gives a positivity rate.

## Sources

- HGNC HGNC:20692: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:20692
- UniProt Q8IWU9: https://www.uniprot.org/uniprotkb/Q8IWU9/entry
- NCBI Gene 121278: https://www.ncbi.nlm.nih.gov/gene/121278
- Ensembl ENSG00000139287: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000139287

## Connected records

- collections: [Open Targets Platform](https://onco.cc/collections/open-targets/)
- cancers: [Neuroendocrine tumours](https://onco.cc/cancers/neuroendocrine/)

---
JSON: https://onco.cc/api/v1/entities/tph2.json