In this analysis, baseline characteristics recognized in EULAR and GRAPPA guidelines as PPFs in PsA (joint erosion score, CRP level, extra-articular manifestations such as enthesitis and dactylitis, and level of disease activity; Table 2) [7, 8] were prospectively identified and investigated for their potential to predict response to abatacept in a population of patients with active disease. The gene discussed is CRP; the disease is enthesitis.