EPO and type 1 diabetes mellitus: We evaluated the statistical power of the current study to detect association at the EPO variant assuming an odds ratio of 0.66 (95 % CI: 0.58–0.76) for the additive effect of protective allele (effect size of the two replication cohorts, GoKinD and Boston T1D, in the original report) and an allele frequency of 0.42.