Although loss of CK20 and CDX2 is commonly observed in right-sided colorectal carcinoma [15,16] with high tumor grades and high microsatellite instability, the progressive increase of vimentin immunoreactivity may indicate that the sarcomatous dedifferentiation occurs in late stages of rhabdoid carcinogenesis and could be a crucial event in the transition from adenocarcinoma to RCT [1-3]. The gene discussed is KRT20; the disease is adenocarcinoma.