Scientists are also using SNPs to calculate risk factors associated with cancer in large populations.

First, imagine analyzing the SNPs in a random population of 100 people. 80 percent are found to have SNP A and the remaining 20 percent have SNP B. Now look at another 100 people, all with kidney cancer. In this group, 60 percent have SNP A and 40 percent have SNP B. Neither SNP A nor SNP B causes cancer. However, from this data, physicians can say that a person who has SNP B is at a higher risk for kidney cancer than a person with SNP A.