STAT3 and diffuse large B-cell lymphoma: Additionally, the overexpression of sphingosine kinase 1 (SPHK1), an enzyme responsible for the production of sphingosine-1-phosphate (S1P), serves as a potent driver of angiogenesis in DLBCL, by activating endothelial cells which results in additional STAT3 activation and angiogenesis in the tumor microenvironment [87,120,121].