In 2007, Sinha et al. [23], used the spontaneously metastatic 4T1 mouse mammary carcinoma, and demonstrated that MDSCs impaired tumor immunity by suppressing T cell activation as well as interacting with macrophages to increase IL-10 and decrease IL-12 production, thereby promoting a tumor-promoting type 2 response, a process which can be partially reversed by gemcitabine. The gene discussed is IL10; the disease is breast carcinoma.