recently demonstrated that this accelerated S‐phase entry, triggered by elevated cyclin E expression, induces replicative stress in cancer cells, which results in prolonged G2 arrest and final mitosis‐bypass in a p53‐p21 axis‐dependent manner.[44] In G2‐arrested cells, p53 regulates the CKI p21 to suppress CDK activity. Here, CDKN1A is linked to cancer.