Accordingly, STAT6 knock-out mice (STAT6 -/- mice) have markedly enhanced anti-tumor immunity, as demonstrated by a reduced incidence of spontaneous primary tumors, significantly slower growth of xenografts, a drastically reduced incidence of metastases, and a very low recurrence rate of surgically excised aggressive primary tumors when compared with STAT6 +/+ mice [71-76]. Here, STAT6 is linked to neoplasm.