Despite a shortage of people consenting to donate corneas, heart valves, skin and other tissue after their death, the U.S. bars many gay and bisexual men from becoming tissue donors. Several dozen Democratic lawmakers, including U.S. Reps. Joe Neguse of Lafayette and Jason Crow of Aurora, along with U.S. Sen. Michael Bennet, are calling on the Food and Drug Administration to change a policy that says men who have had sex with men in the previous five years can’t donate tissue. The agency has already moved to revise similar policies around blood donation.