BCL2 and neoplasm: Among them, miR-15a can induce apoptosis and reduce vascular injury caused by ischemia by regulating the post-transcriptional level of Bcl-2.46, 47, 48 miR-21 is highly expressed in many tumours; is involved in cell proliferation, polarization, and apoptosis; and plays an important role in the development of tumours.49