CDK2 and colorectal carcinoma: Cyclin D1 is an important cyclin to be elevated by growth factors during G1 phase of cell cycle and is considered to be a key mediator of extracellular signals that regulate cell growth.21, 22 Amplification of CDK2 also often occurred in tumorigenicity with high proliferation rate.23 Since cyclin D1 and CDK2 are the key cell cycle‐related genes controlling cell proliferation, our results confirmed that circPRMT5 could promote cell proliferation of CRC via regulating cyclin D1 and CDK2 expression.