The function and structure of many disease gene products are currently poorly understood, and the easiest way to proceed is to search databases for homologous proteins to infer function or structure from the closest database match. Bioinformatics provides a variety of methods that reach beyond the standard database searches with single query sequences. The identification of a large superfamily of ribosome-associated proteins by computer analysis enabled Eugene Koonin to infer functional information for Gadd45, which is part of a cell-cycle checkpoint pathway defective in ataxia-telangiectasia.