PTPRC and neoplasm: ctDNA may also capture the HR status from tumor cell populations without EpCAM expression, which could explain the concordant absence of HRD(ctDNA) and of HRD(CyTOF) in cells from patient #55 when gating via CD45−/panCK+ rather than via the stringent CTC marker combination CD45−/panCK+/EpCAM+ (Tables 1 and S5).