The difference between results of OPN in the chronic liver disease (CLD) group in the study of Kim J et al. (median 381 ng/mL; limits: 29–1688) and our (median: 946.30 ng/mL; limits: from 337.10 to 3583.00) may be due to the fact that they had only 50 % of cirrhosis in the CLD group, while in our case, all the patients had cirrhosis (and thus greater severity of liver disease). This evidence concerns the gene SPP1 and congenital secretory chloride diarrhea 1.