Samuel J. Martínez‐Domínguez, Olga P. Nyssen, Ángel Lanas, Enrique Alfaro, Laimas Jonaitis, Umud Mahmudov, Irina Voynovan, Babayeva Gülüstan, Luis Rodrigo, Giulia Fiorini, Ángeles Perez‐Aisa, Javier Tejedor‐Tejada, Bojan Tepes, Ludmila Vologzanina, Emin Mammadov, Frode Lerang, Quliyev Fərid Vidadi Oğlu, Natalia V. Bakulina, Rustam Abdulkhakov, Ilchishina Tatiana, Thomas J. Butler, Aiman Silkanovna Sarsenbaeva, Renate Bumane, Alfredo J. Lucendo, Marco Romano, Luis Bujanda, Sayar R. Abdulkhakov, Oleg Zaytsev, Manuel Pabón‐Carrasco, Alma Keco‐Huerga, Maja Denkovski, Jose M. Huguet, Monica Perona, Óscar Núñez, Matteo Pavoni, Galyna Fadieienko, Sergey Alekseenko, Sinead M. Smith, Luis Hernández, Juozas Kupcinskas, Dmitry S. Bordin, Mārcis Leja, Antonio Gasbarrini, Oleksiy Gridnyev, Anna Cano‐Català, Pablo Parra, Leticia Moreira, Francis Mégraud, Colm O'Morain, Javier P. Gisbert, the Hp‐EuReg Investigators