To test the hypothesis that p21 helps to maintain cell viability in TP53WT NSCLC cells, we used CRISPR/Cas9 to disrupt the p21 gene (CDKN1A) in our five TP53WT NSCLC cell lines to generate p21 knockout (p21KO) cell lines. The gene discussed is CDKN1A; the disease is non-small cell lung carcinoma.