CXCR4 contributes to tumor progression and metastasis of solid tumors through two distinct pathways that are both G protein-dependent (AKT, PI3K, mTor, EGFR, among others) and -independent (JAK/STAT, p53, MAPK, ERK, among others) [14,15,16,17]. The gene discussed is CXCR4; the disease is neoplasm.