IL10 and cancer: In addition, direct inhibition of the immune mechanism occurs due to vascular endothelial growth factor (Gabrilovich et al., 1996), prostaglandin E2 (Benefield et al., 1996; Schroeder et al., 2004), transforming growth factor-β (TGF- β) (Qin et al., 2001), and interleukin (IL)-10 secreted from cancer cells (Dennis et al., 2013), further decreasing the function of anti-cancer immunity.