Given that c‐Myc represses p21 expression via binding to the p21 promoter,27 and that cellular senescence has been reported to be responsible for tumor regression upon c‐Myc inactivation.,28 we examined the expression of c‐Myc and found that abemaciclib treatment decreased their expression of c‐Myc. The gene discussed is MYC; the disease is neoplasm.