Results: RET protooncogene (chr10:43609933, c.1886_1891delTGTGCG, p.Leu629_Asp631delinsHis) was found to be present in the MTC tissue of the primary tumour, lymph node, and distant metastasis in the Cancer Hotspot Panel diagnostic, while the other investigated therapy-relevant mutational profiles were not consistently found. Here, RET is linked to neoplasm.