CDK4 and neoplasm: The evaluation of the combinatory effect of CDK4/6 inhibitor (Abemaciclib), CDK2 inhibitor (Fedraciclib), and CDK7 inhibitor (Samuracciclib) on the efficacy of anti-PD-L1 immunotherapy in their in vitro and in vivo xenograft models of MDA-MB-231 and 4T1 cells [46] showed that the combination of CDK4/6 inhibitor and CDK7 inhibitor with anti-PD-L1 immunotherapy respectively, significantly inhibited tumor growth in the xenograft models [46].