From the health to hepatitis, the MIF signaling network and related ligand-receptor interactions, including MIF-(CD74 + CXCR4), MIF-(CD74 + CXCR2), and MIF-(CD74 + CD44) showed a significant effect on macrophage–naïve CD4 + T cell interaction (Fig. 3B and E). Here, CD74 is linked to hepatitis A virus infection.