HMGCS1 and hypothyroidism: In the frontal cortex in the hypothyroidism model, the decrease in the level of the active form of SREBP-2 was accompanied by a reduction in the concentration of factors involved in cholesterol biosynthesis and regulated by this transcription factor, namely 3-hydroxy-3-methylglutaryl-coenzyme A synthase-1 (HMGCS1) and 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR).