Altogether with NPM1, these are three autoantigens present in SLE patients.47–49 We, therefore, examined whether HSP90α and RPLP0 were cleaved after C1 treatment by western blotting, but neither was cleaved unlike NPM1 and HMGB1 which were effectively cleaved (Figure 5c). Here, HMGB1 is linked to systemic lupus erythematosus.