CXCR4 and neoplasm: The CXCR12/CXCR4 axis has emerged as a potential therapeutic target through the activation of multiple signaling pathways, such as ERK1/2, Ras, p38 MAPK, PLC/MAPK, SAPK/JNK, and regulation tumor stem cells, which play a vital role in tumor initiation and progression (146, 147).