At present, an important role in the pathogenesis of thyroid autoimmune diseases is played: FasL molecule and Fas receptor, inhibitor molecule like Bcl-2 protein, and the most common mutations in thyroid cancer include RET/PTC rearrangement, BRAF mutation, RAS mutation, or finally rearrangements leading to formation of PAX8-PPARg fusion oncogene. The gene discussed is BCL2; the disease is thyroid cancer.