Papillary thyroid carcinomas developed in BrafV600E+/−/Pten+/−/TPO-Cre mice of a pure 129SvJ genetic background (cell lines BB19, BB57, BB342, and BB1845) or a mixed genetic background (cell lines B1865 and B1866). The gene discussed is PTEN; the disease is thyroid gland papillary carcinoma.