ABCB1 and neoplasm: Overexpression of ABCB1 leads to the overexpression of membrane P-gp, with a consequent reduction in the concentration of intracellular paclitaxel, reducing the inhibitory effect of paclitaxel on tumor cells (Schondorf et al., 2002; Lukyanova, 2010; Shen et al., 2016).