The above sections have highlighted how human genetic tools have aided in the identification of genetic variants contributing to the addiction cycle. Yet it needs to be understood that a genetic association characterizes only the first stage in understanding the underlying biology that leads to disease. A genetic association represents not only an association with tested genetic variants, but also an association with untested, highly correlated SNPs that can span across many genes on the same chromosome. A challenge once a genetic association is confirmed is to then understand which of these variants contribute to the biological mechanism underlying the correlation with a disease.
