Draft

The thyroid hormone results in an increase in cyclin kinase inhibitors, p27 in particular. With this upregulation of p27 inhibitors, the cell cycle is arrested at the G2/S restriction point. In order for spindles to form for division to occur, the cyclin-CDK2 complex must be activated. Since thyroid hormones play a role in an increase in cyclin inhibitors, cyclin-CDK2 complex cannot become phosphorylated in order to become active.