This TNF deficiency may also occur endogenously in certain individuals due to decreased leukotriene A4 hydrolase (LTA4H) activity (CC genotype of LTA4H gene), resulting in a decrease ratio of the pro-inflammatory leukotriene B4 (LTB4) to the anti-inflammatory LXA4 (201, 202). The gene discussed is LTA4H; the disease is hyperinsulinemic hypoglycemia, familial, 4.