Major advances in fluorescence-based molecular-imaging technologies, such as FRET and fluorescence fluctuation spectroscopies, and molecular dynamics simulations have spurred the development of exquisite methods for reliably probing protein association in silico, in vitro, and in vivo. The Receptor Interactions and Intracellular Organization Alliance (RIIO Alliance) brings together a group of researchers interested in the relationship between quaternary structure and function of cellular receptors under various environmental conditions, e.g., expression levels, the presence of ligand or other binding partners, and membrane composition and structure. Individual members of the alliance spontaneously collaborate with one or more other members on specific projects, though the alliance itself does not collectively work on a collective project at this time. We meet every couple of years as part of the Milwaukee Symposium or other venues to communicate research, exchange ideas, to help push science forward in this area and build a community of researchers for the benefit of our respective students and trainees.