Therefore, this study aims to determine the association of the CTLA-4-1661G>A gene polymorphism and other factors, such as age, gender, ethnicity, obesity, baseline AST, baseline ALT, baseline HBV DNA, HBeAg, genotype, degree of fibrosis, and CTLA-4 levels with HBV DNA suppression in chronic hepatitis B patients treated with TDF. This evidence concerns the gene CTLA4 and obesity due to melanocortin 4 receptor deficiency.