Although its expression was first considered to be specific to this cell type, studies have demonstrated that Foxp3 protein is expressed as a marker for regulatory T cells (Treg) cells and as an onco-suppressor in several mice models, including breast, prostate, and pancreatic cancers via either as a transcriptional repressor of c-Myc, Skp2, and HER2 gene expression, or a regulator of interleukin (IL)−6 or −8 expression, respectively [14–16]. The gene discussed is ERBB2; the disease is familial pancreatic carcinoma.