Professor Jun Liu studies repetitive patterns in the DNA that lies between genes. This material contains instructions for regulating the expression of genes, and it is involved in whether the proteins produced by genes will become part of a brain or a big toe. These on/off switches can be found by doing difficult, time-consuming experiments that require copying and mutating genes. If a region close to a gene is mutated and the gene stops producing a certain protein, that region must be part of a genetic switch. Liu believes he can locate such switches by statistical analysis. He has made about 2,000 predictions of where switches are located in the bacterium E. coli. His predictions are 80 percent correct.