ABCB1 and neoplasm: It is a 170 KDa phosphorylated glycopeptide encoded by MDR1 gene and expressed in normal tissues, but it is highly overexpressed in several tumor cells [5], where it actively extrudes chemically, pharmacologically, and structurally unrelated anticancer drugs such as paclitaxel, doxorubicin, and vincristine [6,7].