More significantly, a study that included 116 subjects between the age groups of 25–60 years belonging to 72 ethnic groups found in the native African population analyzed for the associations of CAD, CVD, and AD complications showed that the APOE isoform (ε4 carriers) recurrences inferred for the Zambian tribe's ancestry varied significantly between Zambian and the North African populations, such as Moroccans and Tunisians. This evidence concerns the gene APOE and Alzheimer disease.