IL6 and cancer: It had already been established in various in vitro and in vivo studies that the activation of β-adrenoceptors by catecholamines promotes the synthesis of cytokines especially IL-6 [282], cancer cell immunity [283], initiation of tumorigenesis [284], stimulation of tumor-associated macrophage [285], VEGF/FGF2-mediated angiogenesis [286], potentiation of the tumor micro- and macroenvironments [287, 288], and cancer cell proliferation, differentiation, and migration in animal models of various cancers [278, 289–291].