CD8A and neoplasm: Also, in CRC mouse models, it has been demonstrated that treatment with Clostridium butyricum and Bacillus subtilis can decrease cancer incidence, due to a decrease in the number of Th2 and Th17 cells, thereby inhibiting CD4+ and CD8+ T lymphocytes, blocking the cell cycle, reducing the secretion of inflammatory factors such as NFκB and IL-22, and promoting tumor cell apoptosis [121].