The foundation for much of our understanding of basic cellular biology has been learned from the budding yeast Saccharomyces cerevisiae. Studies with yeast have also provided powerful insights into human genetic diseases and the cellular pathways in which they are involved. Here we present an update on new developments at the Saccharomyces Genome Database (SGD; http://www.yeastgenome.org/), the premier community resource for budding yeast. We are expanding the scope of SGD to include high quality manually curated information regarding functional complementation between yeast and human homologs. This new information is provided in meaningful ways allowing data mining and discovery by integrating these data into this encyclopedic online resource. In addition to introducing our presentation of these newly curated data we will highlight other new developments, such as written summaries about yeast genes and their mutant phenotypes, their human homolog disease associations, and presentation of the yeast/human ortholog set. We also associate sequence changes with variations in cellular phenotypes and protein function. SGD maintains these different datatypes, and distributes them to the scientific community via the web and file transfer. These expanded efforts are part of our continuing mission to educate students, enable bench researchers and facilitate scientific discovery. This work is supported by a grant from the NHGRI (U41 HG001315).