IL17A and colorectal cancer: Bacteria within the tumor secrete IL-17, promoting the growth of colorectal cancer by increasing B cell infiltration in the tumor tissue.[66] Symbiotic bacteria stimulate γδ T cells to produce IL-17, enhancing local inflammation in lung cancer and driving tumor development.[20] The fungi in pancreatic cancer enhance the secretion of IL-33, recruiting Th2 cells and ILC2 into the tumor tissue, facilitating tumor progression.[67]