PREX1 and Insulin resistance: This largely confirmed the previously reported insulin resistance in Prex2–/– mice27, but again with some differences to the earlier study, which reported an impaired counter-regulatory response to hypoglycaemia rather in young Prex2–/– mice on chow diet, similar to Prex1–/– mice, whereas we observed true insulin resistance in old Prex2–/– mice on chow diet and middle-aged mice on HFD.