Overused (ordered more commonly than expected e.g folic acid, LDH, chloride orders which have little clinical impact on clinical decision except specific patients) or misused tests (e.g. HBeAg test order for a HBsAb positive patient, TORCH (toxoplasmosis, rubella, cytomegalovirus, herpes) IgG and IgM testing for every pregnant women, preoperative hepatitis and HIV testing, free PSA testing independent from total PSA levels) were reviewed. The gene discussed is CD40LG; the disease is Hepatitis.