BRCA1 and cancer: To evaluate whether the expression levels of BRCA1 and RAD17 were different by the presence or absence of TP53 mutations in human cancer samples we carried out RT-qPCR analysis in matched tumour and normal tissues from 63 head and neck squamous cell carcinoma (HNSCC) patients, of which 32 presented tumors with a mutated TP53 and 31 with a wild-type TP53 gene (Supplementary Table 3).