ATR and obesity due to melanocortin 4 receptor deficiency: However, there was a tendency towards elevated levels of phosphorylated ATM (pATM) (Fig. 3a), ATR (pATR) (Fig. 3b), H2AX (γ-H2AX) (Fig. 3c) and KAP1 (pKAP1) (Fig. 3d) in subjects with obesity.