Although there was no evidence that adenyl cyclase 9 polymorphisms were associated with severe malaria outcomes in a large study of cases from Malawi and The Gambia [39], SNPs in two other genes in the Gs signal transduction pathway - adenosine receptor 2 (ADORA2A) and G-alpha-s (GNAS) - have been linked to altered risk of severe malaria in multicentre studies in The Gambia, Malawi and Kenya [39], [40]. This evidence concerns the gene ADORA2A and malaria.