CXCR4 and neoplasm: Upon binding of CXCL12 with CXCR4, signalling events activate multiple downstream signalling pathways, including phosphoinositide 3-kinase (PI3K)/AKT, mitogen-activated protein kinase (MAPK/ERK), and janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathways, facilitating tumour cell survival, proliferation, migration, and immune evasion [13].