CDK1 and neoplasm: Our previous paper reported that (1) TOPK suppression increases sensitivity to irradiation in a tumour-specific manner; (2) TOPK suppression alters G2/M checkpoint activity in tumour cells by blocking inhibitory phosphorylation of Cdk1; and (3) TOPK suppression promotes radiation-induced tumour cell death by retaining post-IR chromosomal damage and increasing the rate of multinucleation following cell division [10].