CXCR4 and cancer: Additionally, TPBG modulates cell adhesion, cytoskeletal organization, and mobility by facilitating functional C-X-C chemokine receptor type 4 (CXCR4) expression, leading to C-X-C motif chemokine 12 (CXCL12)-mediated chemotaxis in differentiating ES cells, embryonic fibroblasts, and cancer cells15–18,20.