In a study involving men with T2DM (n = 12), a single HBOT session improved insulin sensitivity in both adipose and skeletal muscle tissues, increased phosphorylation of insulin receptor substrate 1 (IRS-1) and activation of protein kinase B (Akt), and simultaneously reduced endoplasmic reticulum (ER) stress [10]. The gene discussed is AKT1; the disease is type 2 diabetes mellitus.