To investigate expression of these cytokines in MAIT cells, we incubated PBMCs from 4 gastric cancer patients, 3 colon cancer patients, 3 lung cancer patients, and 10 HCs for 4 hours in the presence of PMA and IM; then the expression of IFN-γ, IL-17, and TNF-α in the MAIT cell population was examined at the single-cell level by intracellular flow cytometry (Figure 3A). Here, IL17A is linked to lung cancer.