ABCB1 and hepatocellular carcinoma: Cytogenetic abnormalities indicate genetic instability and most likely explain the frequency observed in TEC resistance to chemotherapeutic agents, such as renal carcinoma-derived TEC resistance to vincristine [26], hepatocellular carcinoma-derived TEC resistance to 5-fluorouracil and adriamycin [41,42], and tumor-derived VEGF-mediated TEC resistance to paclitaxel with ATP-binding Cassette Sub-family B Member 1 (ABCB1) upregulation [42].