While tumor cells mediate tumor angiogenesis by secreting soluble factors such as VEGF and PDGF that enhance endothelial cells proliferation, migration and vessels formation (62, 63), endothelial cells secrete wide range of pro-inflammatory cytokines and chemokines (e.g. IL-1β, IL-6, TNF-α, CXCL1 and CCL2 (64, 65) that stimulate cancer cells and non-malignant cells within the tumor microenvironment, important process in potentiating inflammatory responses and immune cells activity regulation. Here, IL6 is linked to cancer.