Among the European countries, such as the UK, Sweden, Spain, Finland, Germany, Greece, Italy, Belgium, Hungary, Austria, Poland, and Norway, there is a high frequency of CD33 rs3865444 in a large population of 8,794 cases and 10,917 controls, which is associated with AD (Carrasquillo et al., 2011; Lambert et al., 2013). Here, CD33 is linked to Alzheimer disease.