ERBB4 and thyroid gland undifferentiated (anaplastic) carcinoma: The down-regulated genes included thyroid differentiation signature genes such as TG, TTF1, TSHR and TPO (Additional file 2: Figure S2) in addition to the tumor suppressor FHIT. Genes believed to be cancer drivers and to serve as drug targets in other malignancies showed consistent down-regulation in anaplastic thyroid cancer; these included ERBB4, NTRK2, FGF7 and MAPK10 (Additional file 2: Figure S3).