Similarly, voruciclib, a CDK4/6 inhibitor (Gupta et al., 2018; Gupta et al., 2018), significantly increased the ATPase activity of P-gp and inhibited the efflux of paclitaxel or mitoxantrone from human colorectal adenocarcinoma SW620/AD300 cells overexpressing P-gp and non-small cell lung cancer NCI-H460/MX20 cells overexpressing BCRP, respectively, thus reversing the MDR mediated by P-gp and BCRP, respectively (Gupta et al., 2018). Here, ABCG2 is linked to colorectal adenocarcinoma.