ERBB4 and medullary thyroid gland carcinoma: Additionally, these data showed differential expression of the ErbB family of receptor tyrosine kinases in T1/FTC and T2/MTC groups, with ERBB2 significantly up-regulated in T1/FTC samples, and both ERBB4 and EGFR genes significantly up-regulated in T2/MTC samples (Supplementary Fig. 1).