Considering the limitation of sample size in this study, as well as possible ethnic variations in the population, further studies with larger samples and in other populations are recommended to better analyze these genotypes and their respective doses of TNF-α serum, to better assess whether there is a connection between the TNF-α (-G308A) polymorphism and the expression of TNF-α and UGIB intensity in schistosomiasis. Here, TNF is linked to schistosomiasis.