SMARCA4 and neoplasm: In addition, the immunohistochemical analysis of FFPE tumour tissue revealed tumour‐specific complete loss of SMARCA4 nuclear staining, in keeping with the presence of biallelic inactivating mutations in SMARCA4. Notably, as the primary antibody recognizes an N‐terminal epitope located upstream of both p.Arg979* and p.Gln413Argfs*88 truncating mutations (amino acids 200–300), the complete absence of detectable protein expression is consistent with nonsense‐mediated decay of both germline and somatic mutant transcripts (Figure 4C).