PGP and neoplasm: Attributed to their clear Pgp interaction properties as well as their considerable effect on Pgp substrate cellular accumulation, Cur-3 (ATPase inhibitor, cytotoxic) and Cur1-12V (Direct Pgp inhibitor, no cytotoxic activity) would be good candidates to improve the activity of Pgp substrate drugs (such as paclitaxel) within Pgp expressing tumor cell types (such as LS-174T colorectal cancer cells).