An in vitro experiment indicated that exosomes secreted by EGFR‐mutant non‐small cell lung cancer cell lines PC9 and HCC827 were more capable of promoting CD8 T cell apoptosis than EGFR wild‐type cell lines H1299 and SK‐MES‐1 (P = 0.007 and P = 0.010, respectively). This evidence concerns the gene CD8A and lung cancer.