Otherwise, these divergent results of association, whereas a similar frequency of the Q-121 allele was observed in both studies, could be explained by a modest contribution of the ENPP1-K121Q variant to the risk of T2D in Tunisians at the population level, and also in interaction with BMI and environmental factors in modulating T2D risk, as previously reported [33]. This evidence concerns the gene ENPP1 and type 2 diabetes mellitus.