In addition, the catecholamines norepinephrine and epinephrine can promote tumor cell proliferation, pro-inflammatory cytokine secretion such as IL-6 and IL-8, and modulate vascular endothelial growth factor (VGEF), which could downregulate the expression of DNA repair genes in addition to altering natural killer (NK) cell activity [29]. Here, CXCL8 is linked to neoplasm.