CXCR4 and cancer: [60–62] Other signaling pathways with established roles in promoting cancer metastasis were also significantly expressed in hybrid cell populations including GAS6-AXL [35] (tumor-hybrid), CXCL12-CXCR4 [36] (hybrid- T cells), LGALS9-P4HB [37] (hybrid-tumor), and IGF1-IGF1R [38–41] (hybrid-tumor).