CD8A and cancer: Importantly, CDKN2A upregulates expression of cyclin-dependent kinase 4 (CDK4)/CDK6 [15], the corresponding selective inhibitors of which, such as palbociclib, ribociclib, and abemaciclib, interfere with cell cycle progression, induce cell senescence, and promote cancer cell disruption through a cytotoxic CD8+ T cell-mediated effect [22].