KLF4 and malignant colon neoplasm: Interestingly, Caco-2 cells resembled non-transformed CCD841 cells, as well as certain human primary colon cancers (Cases 9 and 15, Figure3), in having low expression levels of both miR-206 and KLF4. The latter signature appeared to involve slower cell proliferation and doubling time, although further work is needed to clarify this possibility, especially in vivo.