In addition, with the condition of cellular stress, GDF-15 and other cytokines produced by fibroblasts, such as granulocyte-macrophage colony stimulating factor, interleukin-12 (IL-12), or chemokine c-x-c motif 12 (CXCL-12), act on nearby cells to promote tumor cell proliferation and tumor growth94. This evidence concerns the gene CXCL12 and neoplasm.