GPT and obesity due to melanocortin 4 receptor deficiency: According to HBV markers, HBV carriers can be divided into different categories: 1) potential occult HBV infections (pOBIs), characterized by HBsAg negativity, positivity for antibodies to the core antigen (anti-HBc), very low (<200 international units (IU)/mL), or absent HBV-DNA levels, and alanine aminotransferase (ALT) persistently within normal range, unless other potential hepatotoxic agents or conditions (i.e., obesity, alcohol, drugs) may increase this latter test; 2) overt carriers, characterized by HBsAg positivity.