DIO2 and hypothyroidism: However, despite the increase in plasma levels of free T3 and T4 caused by the daily treatment with Kp-10, it is suggested that the local availability of T3 in the placenta has not changed, since the treatment with Kp-10 did not change the lower placental expression of Dio2 caused by hypothyroidism, the enzyme responsible for the intracellular availability of T3 (62).