AKT1 and angioosteohypertrophic syndrome: Immunohistochemistry revealed that the vessels in all 14 patients and the adipose tissues in 13 patients expressed p-AKT, p-mTOR, and/or p-4EBP1 (Fig. 3; Table 3), indicating enhanced activation of the PI3K/AKT/mTOR pathway in mesenchymal tissues compared with that in normal tissues in these patients with KTS.