PIK3CA and breast neoplasm: Would a mouse model of Ikbke-induced breast cancer show cooperation with mouse models of activated Pik3ca? Indeed, IKBKE is amplified and overexpressed together with PIK3CA mutation in some human breast tumors suggesting that these mutations can cooperate (e.g. MCF7 cells show IKBKE amplification/overexpression and PIK3CAE545K mutation [141, 154]).