CCND1 and cancer: One of its two isoforms, cyclin D1b is important for the malignant phenotypes of human UBC cells via suppression of apoptosis, induction of cancer cell stemness and epithelial–mesenchymal transition.25 Altered expression of cyclin D1 was reported to be associated with lymph node metastasis and risk of recurrence of UBC.26 As a binding partner of cyclins, cyclin‐dependent kinase 1 (CDK1) is also a key player in cell cycle regulation.