NTRK1 and thyroid tumor: In this review, we discuss the applications of six “next-generation” immunohistochemical markers, namely BRAF V600E (clone VE1), RAS Q61R (clone SP174), pan-TRK (clone EPR 17341), ALK (clones 5A4 or D5F3), PTEN, and β-catenin in the pathologic diagnosis and molecular classification of thyroid tumors.