CDK4 and cancer: CDK inhibitors, in particular CDK4/6 inhibitors (Abemaciclib, Palbociclib and Ribociclib), induce cell-cycle arrest and subsequent senescence in several cancer cell lines and mouse models (Asghar et al., 2015; Alvarez-Fernandez and Malumbres, 2020; Carpintero-Fernandez et al., 2022).