More than twenty years after the first bacterial genome has been sequenced, microbiologists are faced with an avalanche of genomic data. However the quality of the functional annotations of the sequenced proteome is very poor with more than half of the sequenced proteins remaining of unknown function. After taking this course, students should master an array of web-based tools to help to predict gene function. This will allow them to generate in silico based functional predictions and produce illustration for manuscripts that use comparative genomic methods. For background read (https://www.ncbi.nlm.nih.gov/pubmed/20001958)