  Thyroid cancer is the commonest endocrine malignancy. Mutation in the BRAF
serine/threonine kinase is the most frequent genetic alteration in thyroid
cancer. Target therapy for advanced and poorly differentiated thyroid
carcinomas include BRAF pathway inhibitors. Here, we evaluated the role of
MAP3K8 expression as a potential driver of resistance to BRAF inhibition in
thyroid cancer. By analyzing Gene Expression Omnibus data repository, across
all thyroid cancer histotypes, we found that MAP3K8 is up-regulated in poorly
differentiated thyroid carcinomas and its expression is related to a stem cell
like phenotype and a poorer prognosis and survival. Taken together these data
unravel a novel mechanism for thyroid cancer progression and chemo-resistance
and confirm previous results obtained in cultured thyroid cancer stem cells
