AKT1 and medullary thyroid gland carcinoma: AKT phosphorylation at Thr308 (phospho-Thr308) and Ser473 (phospho-Ser473) were detected in all mouse MTC tumors, demonstrating that the PI3K/AKT pathway is activated in these tumors, as observed in MTC patients [27, 28] (Figure 6A).