To further investigate non-additive interactions between SLC2A9 genotype and environmental exposures in control of urate levels and risk of gout a series of classical interaction tests focused on putative instrinsic and extrinsic interactors could be conducted as has been performed previously (McAdams-DeMarco et al., 2013; Batt et al., 2014; Voruganti et al., 2014). This evidence concerns the gene SLC2A9 and gout.