Considering somatic variants, RET GoF pathogenic variants are found in approximately half of sporadic MTC cases (Ciampi et al. 2019), and activating RET chromosomal rearrangements or gene fusions constitute oncogenic drivers in multiple solid tumours, including 10–20% papillary thyroid cancers (PTCs) (Agrawal et al. 2014) and 1–2% of NSCLC (Takeuchi et al. 2012). This evidence concerns the gene RET and medullary thyroid gland carcinoma.