In vitro, OSM mediates tumorigenesis by activating STAT3 or STAT1 thus promoting expression of genes responsible for cell migration, ECM remodeling, and angiogenesis including, PLAU (plasminogen activator of urokinase), CHI3L3 (chitinase-like protein 1) and VEGF in several different human brain tumor cell types (183, 187, 249). This evidence concerns the gene STAT3 and brain neoplasm.