Indeed, had the reduced-function OGA mouse (with increased O-GlcNAc levels) shown improvement in EF during heart failure, the urgency to identify protein targets would be clear; however, we observed that either deletion of Ogt [19] or reduction of Oga—which have opposite effects on global O-GlcNAc levels—culminates in exacerbation of heart failure. Here, OGA is linked to heart failure.