KRT14 and neoplasm: However, once tumors are established, PyMT+/−Rank+/tg tumor cells showed fairly increased tumor initiating ability compared to single PyMT+/− tumors, in line with their enhanced stemness and metastatic potential, probably due to the accumulation of luminal progenitor populations CD61+ and CD49b+ and embryonic-like dual positive CK14/CK8 cells [18].