In the recently published prospective trial of propranolol (along with cyclooxygenase-2) in early-stage breast cancer patients prior to surgery, one treatment arm patient experienced nausea as a side effect (5% of the treatment arm population) and subsequently withdrew from the study; there were no reported episodes of hypotension, though the continued propranolol dose was low at 20 mg bid [28]. The gene discussed is PTGS2; the disease is breast cancer.