CEACAM5 and malignant colon neoplasm: In addition to growth inhibition, treatmentof colon cancer cells with PPARγ ligands promotes tumor cell differentiation asassessed by increased cytoplasmic to nuclear ratio and higher levels ofdifferentiation markers such as carcinoembryonic antigen (CEA), villin,intestinal alkaline phosphatase, GOB-4, and keratin 20 [27, 29, 47].