CDK4 and cancer: However, as shown in Table 2, some cancer cells can overcome the G1 checkpoint and progress to the S and G2 phases despite CDK4/6 inhibition, as shown in the work of Pandey et al. [72], in which the CDK4/6 inhibitor Palbociclib was combined with Eribulin to destroy cells that escaped to the following phases of the cell cycle.