CXCR4 and infection: The data also showed that MAIT cells expressed more CD69 (gut aGVHD vs. no-event, p = 0.02; gut aGVHD vs. infection or fever, p = 0.011; Figure 6E), CXCR3, and CXCR4 in the gut aGVHD group than in the other two groups.