Similarly, in small cell lung cancer, the CXCL12/CXCR4 axis could promote integrin activation, thereby increasing drug resistance and promoting tumor cell growth [8], while in pancreatic cancer tissues, the expression of CXCL12 suggested that the CXCL12/CXCR4 axis could promote the proliferation, migration and invasion of pancreatic cancer cells through a paracrine mechanism [9]. This evidence concerns the gene CXCR4 and small cell lung carcinoma.