CXCR4 and cancer: Detailed researches on the functions of CXCL12‐CXCR4/CXCR7 pathways and their cross‐talks with CXCR3, CXCL11, CXCL10, and CXCL9 remain urgently warranted, which help lead to safer and more efficient use of their molecular inhibitors in targeted cancer therapy.