1. Department of Pathology, Bahrami Children Hospital, Affiliated with Tehran University of Medical Sciences, Tehran, Iran
2. Roshan Azma Pathobiology Lab, Private Lab Specialized in Pediatric Gastrointestinal and Hepatic Pathology, Tehran, Iran
3. Department of Pediatric Gastroenterology, Hazrat-e Rasool Hospital (Affiliated with Iran University of Medical Sciences), Tehran, Iran
4. Department of Pathology, Tehran University of Medical Sciences, Tehran, Iran.