As adenoviral GCP‐2 was not tagged, it was not possible to distinguish it from endogenous GCP‐2 and verify that adenoviral overexpression in murine osteoarthritis was at the same level for GCP‐2 and GCP‐2‐T; however, apart from the three mutated lysine residues, the adenoviral vectors were identical, produced and titrated at the same time, and the treatment was randomized within each cage. This evidence concerns the gene CXCL6 and osteoarthritis.