Although the appropriate upper reference range for ALT may be 19 U/L in females and 30 U/L in males,9 the upper limits of normal for ALT and AST used by the hospital laboratory for this study were 55 U/L and 34 U/L, respectively, and a cutoff of 250 U/L (almost 5 times the upper limits of normal) for either ALT or AST was chosen as the lowest level appropriate for ordering the acute hepatitis serologies (anti-HAV IgM and anti-HBc IgM) for this analysis. The gene discussed is CD40LG; the disease is Acute hepatitis.