To test the influence of B7-H3 ablation on the spontaneous and induced apoptosis of EGFR-mutated lung adenocarcinoma cells, H3255 KO and HCC827 KO cells were left untreated or treated with 8 μM CPT for 6 h and Annexin-V/7-AAD double staining was performed to determine cell apoptosis. The gene discussed is EGFR; the disease is lung adenocarcinoma.