The underlying mechanism of PD and LEE induced cell apoptosis in SCLC needed to be explored; thus, we performed RNA sequencing in H69AR and H69AR cells treated with CDK4/6 inhibitors, analyzed the differentially expressed genes, and performed KEGG analysis to determine the possible underlying mechanism of PD and LEE induced SCLC cell apoptosis. Here, CDK4 is linked to small cell lung carcinoma.