During mitosis, kinase activities of TOPK is elevated, and TOPK promotes phosphorylation of histone H3, PRC1 (protein regulator of cytokinesis 1), GPSM2 [G protein (heterotrimeric guanine nucleotide-binding protein) signaling modulator 2], and p97 proteins that are essential for the completion of cancer cell cytokinesis [34–36]. The gene discussed is PRC1; the disease is cancer.