Addiction is made up of the environment a person grows up in, behavior and influence. In addition, genetics does play a key role in whether a person struggles with addiction in their lives. The (NIDA) started to research to identify variations that make a person vulnerable to drug addition. This study was done by looking into the DNA that are made up to explain drug addicts. These genes sequences contain specific proteins that help with everyday functions. In 2004, investigators at Howard Hughes Medical Institute did their research and were able to find the specific protein that is made for addiction. The protein was PSD-95. This protein specifically explains the relationship between drug addiction, learning and memory. This article is amazing. It easily explained how genetics plays a role in addiction. This topic is very essential for people to know before starting a family so they know what they are getting into.