Wee1 is a serine/threonine kinase that plays a crucial role in regulating the G2/M checkpoint of the cell cycle by inhibiting cell entry into mitosis through the phosphorylation of Cdc2 (CDK1). Wee1 is primarily located in the cell nucleus, participating in the DNA damage response and cell cycle regulatory signaling pathways to ensure DNA integrity. Its expression varies across different tissues, particularly being prominent in rapidly dividing cells. Mutations in the Wee1 gene or abnormal expression levels are associated with the development of various cancers. In the fine-tuned regulation of cell growth and division, Wee1 plays a vital role and serves as a potential target for cancer treatment.