Ki67, a nuclear nonhistone protein, is expressed by proliferating cells in all phases of the active cell cycle.55 The expression level of Ki67 is closely associated with the proliferation, invasiveness, and clinical outcome of a number of malignant tumours.56 Ki67 is regarded as an important proliferative marker and has been widely adopted in determining the proliferation of cancer cells.26, 55, 56 In line with the in vitro findings, the results showed that the expression of Ki67 was decreased in the TIPE2 group and increased in the sh‐TIPE2 group. The gene discussed is MKI67; the disease is cancer.