AKT1 and breast cancer: In contrast to the results reported herein, the role of AKT1-E17K in mammary cells is more controversial, since it produced no substantial effects in the non-tumorigenic mammary epithelial cell line MCF-10 [22], whereas it is apparently transforming in breast cancer MCF-7 cells [23, 24], a discrepancy likely due to intrinsic differences in the genetic constitution of the cell of origin.