CD44 and colorectal carcinoma: In CRC, a recent meta-analysis suggested that the combination of CD44 and CD133 indicated an approximately sevenfold increase in the tumorigenic potential, while CD133 alone indicated 1.45-foldchange, and CD44 alone indicated twofold increase.28 Moreover, the ability to engraft in vivo in immunodeficient mice was restricted to a minority subpopulation of EpCAMhigh/CD44+ epithelial cells in CRC;23 furthermore, ALDH combined with either CD44 or CD133 could increase the tumor-initiating ability.19,29