SNHG20 is also highly expressed in non-small cell lung cancer, down-regulates the expression of the cell cycle-associated protein kinase inhibitor P21, which has been shown to directly bind to and affect G1/S transformation related kinases such as CyclinD/CDK4, CyclinD/CDK6, and CyclinE/ CDK2, and promotes tumor cell proliferation, induces apoptosis, and leads to cell cycle arrest [14]. Here, CDK4 is linked to non-small cell lung carcinoma.