However, pointing to the complexity of physiological and immunological derangements induced by cholelitiasis and obstructive jaundice, we also show that preoperative cholestasis and hepatic injury, might have a marked influence on perforin-related aspects of cytotoxic T and NK cells and final interpretation of data obtained by classic or laparoscopic cholecystectomy. The gene discussed is PRF1; the disease is cholestasis.