But SNPs are not always the entire story. Even among persons with slow acetylators who are exposed to arylamines, not everyone is at increased risk for bladder cancer. Research studies show that half the population in the United States have slow acetylators, and yet far fewer people, about one in 500, get bladder cancer. So having a "slow acetylator" does not automatically mean that you will get bladder cancer after arylamine exposure. Some other genes and their proteins must also be involved in affecting a person's risk for the disease. Researchers have yet to discover the full set of "risk" genes involved.