BRCA2 and neoplasm: The two tumours exhibiting a complete response and one tumour exhibiting a partial response did not exhibit secondary mutations.23 Sequencing of two samples of olaparib‐resistant tumours from clinical trials identified secondary BRCA2 mutations that restored the ORF of the gene.90 However, in another study, deep sequencing of six olaparib‐resistant tumours indicated no evidence of secondary BRCA mutation.33