CD74 and neoplasm: In the subsequent analysis of the potential pathways between GrB+ B cells and tumor cells, the most important incoming and outgoing L-R pairs were the signaling complexes, macrophage migration inhibitory factor (MIF) -(CD74 + CXCR4) and lymphotoxin-alpha (LTA)–(LTB + LTBR), respectively (Fig. S3B, C, Fig. 3C, D).