IL6 and cancer: Isoproterenol, a β-AR agonist, regulates the release of VEGF through β-AR receptors, increasing the vascular distribution in the femurs of mice and the release of the proinflammatory cytokines interleukin-1 (IL-1) and interleukin-6 (IL-6), changing the adhesion state of endothelial cells and promoting bone metastasis of cancer cells (51).