BECN1 and breast neoplasm: BECN1 and BRCA1 were each deleted in approximately one-third of the breast tumors in both the TCGA and METABRIC datasets (BECN1 deletion in 34% in TCGA and 33% in METABRIC; BRCA1 deletion in 35% in TCGA and 27% in METABRIC) (Supplementary Table 2).