Genetic testing identifies changes in chromosomes, genes, or proteins. If that were true for one gene, then why not all the human genes? Genetic approaches include screening for behavioral changes in animals with mutations in K channel genes. Proteins are assembled from amino acids using information encoded in genes. These processes are orchestrated by proteins known as tumor suppressor genes. Mutations in one of more than 50 genes are involved. But the mechanism of storing genetic information (i.e., genes) in DNA was unclear. Examples of human protein-coding genes. Reduced expression of DNA repair genes disrupts DNA repair. Some of the susceptibility genes may be population specific. Benzene metabolism involves enzymes coded for by polymorphic genes. EB is due to a mutation in at least one of 18 different genes. Chickens exhibit various traits affected by pleiotropic genes. Transformation is a complex process dependent on expression of numerous genes. They differ by the order of sequences in pol genes.