Detection and relative intensity of ABCB1 expression in KB-C2 (A) and SW620/Ad300 (B) cells incubated with 10 μM of selonsertib for 0, 24, 48, and 72 h. Detection and relative intensity of ABCG2 expression in NCI-H460/MX20 (C) and S1-M1–80 (D) cells incubated with 10 μM of selonsertib for 0, 24, 48, and 72 h. Data are mean ± SD, representative of three independent experiments. *p < 0.05, compared with control group (KB-3–1 [A], SW620 [B], NCI-H460 [C] and S1 [D]).