PDK1 and neoplasm: More importantly, to determine the biological effects of PDK1 overexpression on ERBB2-induced transformation in vitro and tumor growth in vivo, a set of four human mammary epithelial cell lines MCF10 A were generated by transfection of retroviral vectors expressing PDK1 (+PDK1), expressing ERBB2 (+NeuT), expressing both (+PDK1 +NeuT), or control vectors.