Tunicamycin also inhibits the expression of ABCG2 and cellular translocation of P-gp in topotecan-resistant W1TR cells and PTX-resistant W1PR cells obtained from the primary ovarian cancer cell line W1 and DOX-resistant LoVo/Dx cells constructed from the colorectal cancer cell line LoVo. This evidence concerns the gene PGP and ovarian carcinoma.