CD74 and graft versus host disease: In contrast, microglia from GVHD mice exhibited increased expression of major histocompatibility complex class I and II MHC genes (i.e., H2-K1, B2m, CD74, and H2-Ab1), as well as chemokine genes (i.e., Ccl2, Ccl3, Ccl4, Ccl5, Ccl7, Ccl12, Cxcl9, and Cxcl10), indicative of an activated inflammatory phenotype (Figure 2E).