To understand the upstream molecular mechanisms involved in miR-204-5p repression in thyroid cancer, miR-204-5p and TRMP3 expressions were evaluated after 5′-aza-2-deoxycytidine, a demethylating agent, and MEK, BRAF, PI3K or IGF-1R inhibitors treatments. The gene discussed is BRAF; the disease is thyroid gland carcinoma.