PGP and malignant colon neoplasm: Another VEGF TKI, vatalanib that failed the Phase III clinical trial in combination with standard FOLFOX chemotherapy in the first-line treatment of patients with mCRC (NCT00056459) (Hecht et al., 2011), was found to inhibit the efflux function of P-gp and ABCG2 in the P-gp and ABCG2-overexpressing colon cancer cells HCT116 and without altering the ABCG2/P-gp mRNA or protein expression levels or the phosphorylation of Akt and ERK1/2.