For example, the G1 and G2 alleles of apolipoprotein L1 (APOL1) are strongly associated with non-diabetic end-stage kidney disease (ESKD) in individuals of African ancestry [26]. These alleles are common in African populations, which partially explains the higher incidence of ESKD as compared with European populations [27]. These alleles likely arose as a result of positive selection because they confer resistance to infection by Trypoanosoma brucei, which causes African sleeping sickness [28]. This evidence concerns the gene APOL1 and human African trypanosomiasis.