ABCB1 and colon adenocarcinoma: To the contrary, earlier study reported modest induction of protein expression of ABCB1 by PHT treatment (1.3 ± 0.1 fold), which was conducted in human colon adenocarcinoma, LS1 80/WI, and its adriamycin-resistant subline, LS1 80/AD5O to determine the effect of range of xenobiotics on expression of ABCB1 [23].