CD28 and rheumatoid arthritis: Kawashiri et al. recently reported a fatal case of acute exacerbation of ILD in a RA patient 10 months after starting tocilizumab [43] No data are currently reported about ILD onset or exacerbation for abatacept (a dimeric fusion protein composed of CTLA4 extracellular domain and human FcIgG1, developed to block the interactions of CD28-CD80/CD86 thus impairs T-cell activation) in RA patients [31].