While the model exhibited more small intestine (SI) characteristics (i.e., active SI-specific genes with most colon-specific genes missing), all absorptive populations expressed high levels of colon-specific ion transporter SLC26A2, and vitamin transporter RBP4 were expressed in all absorptive populations, indicating the model also possesses colon-like features given both Caco-2 and HT29 were CRC-derived. This evidence concerns the gene RBP4 and colorectal carcinoma.