Additionally, after coculture of APCs pretreated with E. coli with MAIT cells from different sources, MAIT cells from tumor tissues secreted lower levels of perforin and GZMB than did those from adjacent nontumor tissues and normal liver tissues; however, the levels of tumor‐promoting cytokines (such as IL‐18) were significantly increased. The gene discussed is IL18; the disease is neoplasm.