Recent findings showed that PAQR4 promotes cell proliferation and metastasis through CDK4-pRB-E2F1 in NSCLC 33, although we also observed that PAQR4 regulates NSCLC cancerous cell proliferation, we concluded that PAQR4 knockdown inhibits cell proliferation by inducing cellular apoptosis instead of regulating CDK4 protein stabilities. This evidence concerns the gene E2F1 and non-small cell lung carcinoma.