SFN and breast cancer: In breast cancer, decreased expression of 14-3-3 sigma was found to contribute to the neoplastic transformation of epithelial cells by proteomic analysis [18]; meanwhile, it was also reported that overexpressed 14-3-3 sigma could delay the cell-cycle progression of breast cancer cells from entering the S phase by blocking the activity of cell-cycle regulatory proteins, such as cyclin-dependent kinases (CDKs) [19].