BRCA1 and skin squamous cell carcinoma: Many HR proteins are described to be mutated in cancer samples as: Breast cancer type 1 susceptibility protein (BRCA1) in breast cancer (9), DNA repair protein RAD51 homolog 2 (RAD51B) in uterine leiomyoma (10) or ATP-dependent DNA helicase Q4 (RECQL4) in basal and squamous cell skin carcinomas (11), pointing out the relevance of the HR in the tumor development.