The fact that all CMTC cells show nuclear/cytoplasmic positivity for β-catenin and negativity for thyroglobulin, while the thyroglobulin expression in the present neoplasm is limited to the tumor cells with nuclear/cytoplasmic negativity for β-catenin and vice versa, fits in well with our proposal of a follicular origin for CMTC. The gene discussed is TG; the disease is neoplasm.