I wonder who was it that voted for it being unethical.
How is it unethical?
I would agree right now to give them tissue samples. In fact, I believe that taking tissue samples from some places, such as the colon (in the part that is closer to the rectum, at least), is almost as safe taking a blood sample from the patient, and probably at least as safe as taking a pill of 500mg of acetaminophen.