Acknowledgement to Reviewers of Microarrays in 2015 1. Introduction The editors of Microarrays would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2015. We greatly appreciate the contribution of expert reviewers, which is crucial to the journal’s editorial decision-making process. Several steps have been taken in 2015 to thank and acknowledge reviewers. Good, timely reviews are rewarded with a discount off their next MDPI publication. By creating an account on the submission system, reviewers can access details of their past reviews, see the comments of other reviewers, and download a letter of acknowledgement for their records. In addition, MDPI has launched a collaboration with Publons, a website that seeks to publicly acknowledge reviewers on a per journal basis. This is all done, of course, within the constraints of reviewer confidentiality. Feedback from reviewers shows that most see their task as a voluntary and mostly unseen work in service to the scientific community. We are grateful to our reviewers for the contribution they make. Andreotti, Gabriella Heller, Gerwin Seidel, Michael Bidarra, Silvia Ingelman-Sundberg, Magnus Seitz, Harald Bouckaert, Julie Iqbal, M. Anwar Signore, Michele Brait, Mariana Jayavelu, Naresh Doni Smedby, Karin Ekström Brander, Christian Jonoska, Natasha Solé, Francesc Braun, Frank K. Kato, Takamitsu A. Somoza, Mark M. Brunham, Liam R. Kelly, Christopher V. Strillacci, Maria Giuseppina Burnside, Rachel Kibriya, Muhammad G. Sugimura, Haruhiko Canevari, Silvana Kidd, Mark Sumoy, Lauro Castiglioni, Bianca Kim, J. Sykacek, Peter Castresana, Javier Klopocki, Eva Terbrueggen, Robert Chandra, Divya Korf, Ulrike Ting, Angela Chen, Xiangning Kschischo, Maik Tombelli, Sara Chu, Chi-Ming Kudithipudi, Srikanth Tong, Tiejun Chung, Brian H.Y. Kunkalla, Kranthi Torisawa, Yu-suke Corfield, Anthony P. Kurth, Ina Townley, Helen E. Craw, Pascal Labaer, Joshua Usui, Kenji Cretich, Marina Labarge, Mark Vaudry, David Damaraju, Sambasivarao Lampe, Paul Vazza, Giovanni Darcy, Isabel Laurenceau, Emmanuelle Vogel, Ulrich De Crescenzo, Gregory Lee, Sheng-An Wang, Yufeng De Paz, Jose Luis Louhelainen, Jari Watts, Lora Talley Dixit, Chandra K. Lu, Huibin Wei, Hairong Dodd, Janice Manzano, Marisa Weinhäusel, Andreas Duverger, Eric McDermott, Jason E. Whelan, Rebecca J. Eder, Iris E. Min, Junhong Wild, Peter J. Efthimiadis, Georgios K Moreno, Miguel Willison, Hugh Emmert-Streib, Frank Nagatani, Naoki Winegarden, Neil Eroles, Pilar Nga, Min En Winssinger, Nicolas Esfandyarpour, Rahim Nicolau, Monica Woodbury, Neal Fernández, Ana Nicolini, Claudio Wright, Gavin J. Filiatrault, Melanie Olsen, Catharina Wu, Wesson Fogel, Brent L. Pasquer, Frédérique Yamada, Tesshi Fukuoka, Junya Pena, Romi N Yamagata, Takanori Gach, Johannes S. Peppelenbosch, Maikel Yao, Jun Ghosh, Gargi Pereira, Julia Santucci Zanella, Fabian Giordano, Antonio Phipson, Belinda Zheng, Bo Gonzalo Claros, M Potashkin, Judith Zhu, Xiangdong Granade, Timothy C. Quagliata, Luca Zhu, Heng Griffin, Robert J. Roupioz, Yoann Ziemssen, Focke Guinney, Justin Schmitt, Joachim Zubarev, Eugene Heemstra, Jennifer M. Segura, Víctor