BRCA1 and ovarian cancer: In human breast and ovarian cancers, BECN1 is often co‐deleted with BRCA1. This led to the hypothesis that BECN1 loss is a passenger event and is only deleted due to its proximity to BRCA1. 45, 46BRCA1 is frequently mutated in familial cases of breast and ovarian cancer, being relatively rare in sporadic cancers, and it is a classical tumour suppressor, as only one copy is sufficient to maintain its function.