IL-17C is also thought to be involved in tumorigenesis: increased expression of Il17c mRNA and IL-17RE protein was observed in lung cancer and hepatocellular carcinoma, respectively17,18, and tumor growth was reduced in Il17c-deficient (Il17c−/−) mice after non-typeable Haemophilus influenza infection17 and in Il17re−/− mice on the Apcmin/+ background19. The gene discussed is IL17C; the disease is lung cancer.