also studied the dose response curves in 34 breast cancer cell lines to evaluate cell-cycle arrest and cell death induced by CDK4/6 inhibitors. Abemaciclib was found to be 5.5 times more potent at inducing cytostasis compared to palbociclib based on GR50 values (the dose required to decrease cell growth by 50%). Here, CDK4 is linked to breast carcinoma.