However, as reviewed in the Introduction, while the evidence that the G1 and G2 variants of APOL1 cause increased resistance to SRA-expressing Trypanosomes is strong, and increased parasite resistance provides a logical explanation for the high allele frequency of G1 and G2 alleles in African-American and sub-Saharan populations, there are no data demonstrating the causality of APOL1 alleles in glomerulosclerosis. This evidence concerns the gene APOL1 and glomerulosclerosis.