According to a 2013 report by the Pan American Health Organization, the proportion of individuals with CD4≤ 200 cells/μl ranges from 10% in Cuba to 58% in Guatemala, with a median of 40% for the region.[32] In North America, Europe, and Australia, proportions of late entry into care (CD4 <200 cells/μl or AIDS-defining conditions) range between 8.8% and 28.7% in 2009–2010 [18, 33]. This evidence concerns the gene CD4 and AIDS.