To make biological sense out of microarray expression data, we developed a useful tool, Gene Annotator for Microarray Analysis (GAMA). GAMA retrieves various types of biological information from a number of public databases and deposits it into a local database that can be queried via web-based annotation tools. GAMA allows researchers to obtain a detailed description of categorized biological information for a single gene or orthologous genes. A researcher can also upload a list of genes out of data analysis into GAMA to retrieve various types of biological information of his choice so that gene expression data can be correlated with biological characteristics. GAMA can be accessed at bioinfo.med.mssm.edu:8080/GAMA.