In contrast, both pre- and clinical data have shown that K-ras mutant lung cancers demonstrate significant infiltration of multiple inflammatory cells, such as myeloid cells, CD8+ T cells, regulatory T cells (Tregs), IL-17-producing lymphocytes, and inflammatory cytokines (e.g., IL-6, IL-8, CXCL1) (10, 11). This evidence concerns the gene KRAS and lung cancer.