Meta-analyses showed that the association of COX-2-selective NSAIDs with the risk of AKI did not achieve a statistical significance,6 or even existed only for Rofecoxib, but not for a COX-2 inhibitor class effect.7 Given AKI requiring hospitalization is relatively rare adverse renal events for NSAID users,8 population-based observational studies were encouraged to assess this infrequent adverse effect. This evidence concerns the gene PTGS2 and acute kidney injury.