CD74 

CD74 (HLA class II histocompatibility antigen gamma chain; HLA-DR antigens-associated invariant chain) is a type II transmembrane protein. CD74 is involved in the formation and transport of MHC class II peptide complexes for the generation of CD4+ T cell responses. Cell surface CD74 serves as a receptor for the cytokine, macrophage migration inhibitory factor (MIF) on many cell types. In immune cells, MIF binding to CD74 induces a signaling cascade that results in regulation of cell proliferation and survival. CD74 has been associated with tumor progression and metastasis. CD74 expression has been suggested to serve as a prognostic factor in many cancers, with higher relative expression behaving as a marker of tumor progression^[1].