ABO and malaria: For example, of the 57 single nucleotide polymorphism (SNP) loci representing 39 “candidate” genes selected for the first phase of the MalariaGEN Consortium large multipopulation case-control studies (MalariaGEN 2008), only five of these loci—the sickle cell-causing allele of the beta-hemoglobin gene (HBB), the “O” allele in the ABO gene that determines ABO blood group, both of which were well established as malaria protective prior to the advent of GWAS studies, G6PD, CD40LG, and ATP2B4—were confirmed (MalariaGEN 2014).