The GPCR Retreat focuses on advances in our understanding of how cells communicate with each other and the environment via G protein-coupled receptors (GPCRs), the largest class of membrane proteins and one of the largest classes of targets for drugs currently on the market. The GPCR Retreat is an annual joint meeting that rotates around locations in the United States and Canada surrounding the Great Lakes region. The first Great Lakes GPCR Retreat was conceived, organized and held in London, Ontario, Canada in October 1999. Since then, the GPCR retreat has expanded its membership and continued without interruption for 15 years, attracting internationally-renowned scientists to present research that at times has fundamentally changed the field. The principal objective of the GPCR Retreat is to provide a venue for students, post-doctoral fellows, and principal investigators from academia and industry to discuss and debate existing and novel concepts in receptor biology. One of the core values of this international meeting is to promote interactions among all participants, particularly between trainees and principal investigators. Registration is capped at 200 participants to promote an intimate environment. Over the years, the meeting has grown into one of the most recognized events in the field. That reputation has led to broad participation from the Great Lakes region and beyond. We are thus honoured to bring this prestigious meeting and world-renowned scientists in Bromont for the 15th meeting of the GPCR retreat.