For example, in invasive breast carcinoma, ectopic overexpression of constitutively active STAT1 prompted the enrichment of myeloid derived suppressor cells and resulted in highly aggressive tumor growth upon transplantation into immunocompetent mice, and gene knock-down of STAT1 in tumors reversed these events and attenuated tumor progression [22]. The gene discussed is STAT1; the disease is invasive breast carcinoma.