Guardians of the Gatekeepers (IMAGE) National Centre for Biological Sciences Caption According to Greek mythology, the guardians of the gates of heaven were known as the Horae or Orai after whom the calcium channel protein, Orai is named. Credit National Centre for Biological Sciences (NCBS), Bangalore Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.