EPCAM and neoplasm: Moreover, our in vivo xenograft studies demonstrated that with a KLF4 overexpression, EpCAM−/CD133− non-stem cells attained an in vivo tumor forming ability comparable to EpCAM+/CD133+ LCSCs, and the tumor specimens from KLF4-overexpressing xenografts had increased levels of both the KLF4 and EpCAM proteins.