Western blot analysis of endogenous CK19 expression in colonic cell lines. All CRC cell lines presented with heterotypic bands at 40 KDa (CK19) and ~37 KDa. Bands from two early-staged cells (SW480 and LS 174T) were weaker than those from two late-staged cells (LoVo and HT-29). The molecular weight of Actin was 43 KDa. Antibodies, mouse anti-human CK19 antibody or rabbit anti-human Actin antibody.