Despite the fact that only 4% of sarcoma carry mutations in BRCA1, the best characterized HRR pathway gene, we found several other alterations, most in the form of amplifications and losses, in essential and associated members of the HRR pathway, particularly in UPS, MFS, LMS, ULMS, DDLPS and MPNST (Fig 1E). Here, HMBS is linked to sarcoma.