BRCA1 and neoplasm: In the sequential model of testing, only patients with germline BRCA1/2 wild-type undergo subsequent tumour BRCA1/2 testing to detect additional somatic BRCA1/2 pathogenic variants (germline-first), or alternatively, only patients with a tumour BRCA1/2 pathogenic variant undergo subsequent germline testing to determine whether the variant is constitutional or somatically acquired (tumour-first).