CDK4 and cancer: Considering that adoptive transfer of VSSP-BMDMs induced tumor cell senescence, this therapy could be combined with senolytic agents such as inhibitors of BCL-2, BCL-XL and BCL-W and cyclin D-CDK4/6 complex inhibitor palbociclib, currently in clinical trials in several cancer types in combination with other therapies [30, 38–40].