CDK4 and cancer: Finally, voruciclib, one of the CDK4/6i with anticancer effects, in combination with the BRAF inhibitor vemurafenib in advanced BRAF-mutant melanoma or with the proteasome inhibitor bortezomib in TNBC xenografts was found to antagonize ABCB1- and ABCG2-mediated multidrug resistance in cancer cells [221].