KRT5 and neoplasm: Finally, MMTV-Cre and WAP-Cre driven conditional deletion of Pten, encoding a phosphatase that controls PI3K pathway activation, results in heterogeneous tumor formation consisting primarily of adenomyoepithelioma expressing markers of both epithelial lineages including alpha smooth muscle actin (αSMA), basal and luminal cytokeratins (KRT8, KRT5, KRT14) and ERα, thus, reinforcing that this pathway is key to regulating lineage plasticity [69, 70].