Cellular uptake of AZD1775 and the positive control, estrone-3-sulfate (E3Sul; a typical substrate for OATP1A2, OATP2B1, and OAT3), in the absence or presence of a specific transporter inhibitor [i.e., 100 μmol/L sulfobromophthalein (Sul) for OATP1A2, 10 μmol/L fluvastatin A (Flu) for OATP2B1, or 50 μmol/L probenecid (Pro) for OAT3] in HEK293 cells with overexpression of (A) OATP1A2, (B) OATP2B1, or (C) OAT3 and their respective vector control cells. Data are expressed as the mean ± SD from three independent experiments, with triplicate in each experiment. **, P < 0.01; ***, P < 0.001.