Transcription factor (TF) activity prediction, using the DoRothEA resource, to identify potential regulons responsible for the signalling and phenotypes associated with HPS in HiFi tumours (online supplemental figure 6A) revealed a strong association with STAT1, STAT2, IFN (IRF1, IRF9) and NFκB (NFKB1, REL, RELA, RELB) TFs (figure 5A). Here, IRF9 is linked to Hermansky-Pudlak syndrome.