RET: a multifaceted gene

The proto-oncogene RET, known as the causative gene of multiple endocrine neoplasia type 2 (MEN2) is also implicated in sporadic thyroid medullary carcinoma and in some differentiated thyroid cancers, via fusion with other genes which drive the expression of truncated and active forms in the follicular cells. It grounds the generic screening of MEN2. Activated RET stimulates the proliferation of host cells and the development of tumors. Activated forms of RET may be targeted by tyrosine kinase inhibitors in medullary thyroid cancers, refractory follicular thyroid cancers and in other cancers, where RET mutations and RET-fusion genes are identified at low frequency.