TPO and thyroid cancer: The combination of BRAFV600E and reduced PTEN expression tended to induce larger and more undifferentiated thyroid cancers in our study, and these data were similar to those in LSL-BrafV600E;Ptenf/f;TPO-Cre mice in which PTC rapidly progressed to poorly differentiated thyroid cancers as compared with LSL-BrafV600E;TPO-Cre mice [36] and also to those in Thyro::CreER;BrafCA/+;Pik3calat-1047R/+ mice, which developed anaplastic cancers as compared with Thyro::CreER;BrafCA/+ mice [37].