Nuclear receptors (NRs) represent a class of ligand-dependent and -independent transcription factors with importance to the regulation of development, reproduction, and metabolism. The emergence of new understanding of the structure, function, and role in disease of NRs provides new insights into the interaction between genetics and the environment, with NRs representing new targets for the development of therapeutic agents. NRs play key roles in bone health and contribute to our understanding of diseases and disorders that result in osteopenia and osteoporosis. The Nuclear Receptor Signaling Atlas (http://www.nursa.org) is an online repository of information about NRs and provides a community-wide resource designed to help catalyze new advances in biology and medicine.