Pgp function, characterized by repeated calcein assays performed on isolated tumor cells, showed further increase at day 184, after 9 additional rounds of chemotherapy, reaching high levels (MAF = 0.56) usually observed in Pgp-overexpressing cell lines, such as HCT-15, CHO K1, and HCT-8, exhibiting a MAF of 0.63, 0.64, and 0.46, respectively [32]. Here, PGP is linked to neoplasm.