The jigsaw puzzle of understanding the causes of disease lies before us: we now have the edges and corners in place. The identification of monogenic disease loci and the common genetic variability that contributes to disease risk is now a tractable problem. The techniques that are necessary for genomewide identification of such rare variants that contributes to disease risk are quickly being refined. There is an enormous amount of filling in to do (including the dissection of the interactions among different genes), and there are formidable challenges, which increased bioinformatic data will help to address. Undoubtedly, there will be surprises, but the boundaries of the task ahead have already been drawn.
