We know that TGcog/cog thyrocytes experience chronic unremitting ER stress (with a swollen ER accompanied by a markedly activated ER stress response), yet the thyrocytes continue to proliferate (3); however, thyroidal expression of the TGrdw transgene in TGcog/cog mice (without changing total TG mRNA or the degree of hypothyroidism, and exhibiting comparable levels of canonical ER stress markers) increases the prevailing level of thyrocyte cell death, which correlates with unsuppressed expression of Cidea mRNA in thyroid tissue (Figure 2). This evidence concerns the gene CIDEA and hypothyroidism.