---
title: "Third Rock Ventures VI, L.P. — Ownership Dossier"
canonical: https://whiteintel.dev/entity/e040295f-69f7-5db4-8439-423fa11de38d
json: https://whiteintel.dev/api/public/dossier/e040295f-69f7-5db4-8439-423fa11de38d
identifier: sec:0001931056
jurisdiction: US
risk: Low
source: WhiteIntel corporate-ownership graph
---

# Third Rock Ventures VI, L.P.

**Type:** Person  
**Jurisdiction:** [US](https://whiteintel.dev/jurisdictions/us)  
**Identifier:** `sec:0001931056`  
**Risk level:** Low  
**Canonical dossier:** https://whiteintel.dev/entity/e040295f-69f7-5db4-8439-423fa11de38d  
**Structured JSON / MCP:** https://whiteintel.dev/api/public/dossier/e040295f-69f7-5db4-8439-423fa11de38d  

## Ownership & control

### Holdings / subsidiaries

- **Septerna, Inc.** (10% owner) — https://whiteintel.dev/entity/73a09cf2-416c-5ce7-8f3a-75597df4840f
- **Septerna, Inc.** (10% owner) — https://whiteintel.dev/entity/73a09cf2-416c-5ce7-8f3a-75597df4840f
- **Rapport Therapeutics, Inc.** (tenpercentowner) — https://whiteintel.dev/entity/cc7bf129-032c-525c-b8a7-d6d6fe412250
- **Septerna, Inc.** (tenpercentowner) — https://whiteintel.dev/entity/73a09cf2-416c-5ce7-8f3a-75597df4840f
- **CARGO Therapeutics, Inc.** (tenpercentowner) — https://whiteintel.dev/entity/a783c33b-8f92-53e0-844a-0233eef54b40
- **Tango Therapeutics, Inc.** (director) — https://whiteintel.dev/entity/6d4760cb-8ca3-5276-a9f6-f4d1e943f421

---

_This is the markdown-for-agents view of the WhiteIntel dossier for **Third Rock Ventures VI, L.P.**. Human view: https://whiteintel.dev/entity/e040295f-69f7-5db4-8439-423fa11de38d · Structured JSON: https://whiteintel.dev/api/public/dossier/e040295f-69f7-5db4-8439-423fa11de38d._

_Risk levels are heuristic investigative leads, not legal determinations of beneficial ownership. Every claim carries a source; an absent edge means "not yet observed in current sources", not "does not exist"._