In the present study, we hypothesized that TEVs released by NSCLC cells bearing mutant EGFR and under IL-1β stimulation are implicated in promoting EMT in cancer cells by the activation of the fibronectin–α5β1 axis and in modulating the immune response by affecting immune checkpoint pathways (PD-1, CTLA-4, and FOXP3) and inflammatory mediators (IL-12, INF-γ, and TNF-α) in peripheral blood mononuclear cells (PBMCs) from lung cancer patients. The gene discussed is CTLA4; the disease is lung cancer.