Of these, 13 were also identified as likely targets of variants associated with overall breast cancer risk, while the remaining 11 genes were specific to ER-negative risk variants: ATM, CCNE1, CUL5, MCHR1, MDM4, NPAT, OCEL1, PIK3C2B, RALB, RP5-855D21. Here, PIK3C2B is linked to breast cancer.