RET and differentiated thyroid carcinoma: Genetic alterations in the rearranged-during-transfection (RET) gene by chromosomal rearrangements or mutations result in constitutively active RET protein tyrosine kinase, which is a key target for cancer therapy.1–3 RET fusion oncogenes are mostly detected in non-small cell lung cancer (NSCLC) and papillary thyroid carcinoma (PTC).