“Intestinal enterokinase deficiency” by Hadorn et al. (19), which was one clinical study, and the first case that was reported about an infant presenting with diarrhea, failure to thrive, and hypoproteinemia edema was shown to have deficiency of intestinal EP, which resulted in the failure to activate pancreatic proteolytic enzymes, emphasizing the significance of EP in digestion and activation of proteolytic enzymes in the pancreas. This evidence concerns the gene TMPRSS15 and hyperinsulinemic hypoglycemia, familial, 4.