STAT3 and neoplasm: In addition, STAT3 hyperactivation is a key step for tumor development in the gp130 757F/F mouse model of gastric tumorigenesis, as demonstrated by a variant of mice displaying reduced STAT3 activity (gp130 757F/Y757F: STAT3+/−) showing negligible tumor development, inflammatory infiltration, angiogenesis, and expression of MMPs [167].