CEP70 and neoplasm: In conclusion, expression of a specific set of marker proteins, high tumorigenicity, differentiation in growth factor-containing medium and within xenografts, formation of spheres, and self-renewal capacity suggest that the colorectal TICs used in this study behaved like bona fide tumor-initiating cells and were therefore valuable as EpCAM-expressing TICs for testing the therapeutic potential of BiTE antibody MT110 in vitro and in vivo.