MKI67 and neoplasm: Ki‐67 is an antigen expressed in proliferating cells and a common marker of cell proliferation; thus, it has been used as the most reliable indicator of tumor cell proliferation.30 We detected Ki‐67 expression in miR‐22 mimic‐ and inhibitor‐transfected cells and then explored the effect of miR‐22 on apoptosis in SCLC by APC Annexin V/PI staining.