The involvement of disruption of vascular homeostasis and angiogenesis in DR draws our attention to the tumor necrosis factor superfamily member 15 (TNFSF15), a newly identified cytokine [29] that is produced largely by vascular endothelial cells (ECs) of established blood vessels in normal tissue [30,31,32], but is absent or marginal in tumor vasculature in various cancers [33,34,35,36,37,38] and in wounded tissues [39]. This evidence concerns the gene TNFSF15 and cancer.