CD276 and pachyonychia congenita: Whilst PD-L1 is expressed in less than a quarter of PC (7,52), B7-H3 overexpression specifically in HRD tumours is in keeping with the evidence that tumours with DDR can activate specific immune evasive mechanisms (31,53), and supports further mechanistic studies of B7-H3 modulation and rational combination therapeutics targeting B7-H3 in these PC genomic subsets.