PROS1 and retinitis pigmentosa 1: In addition, the patients with severe symptoms within the PRN group were more likely to induce higher levels of anti-RBD IgG (p = 0.012; Fig. 1d), which is consistent with previous reports.12 In contrast, there were no significant differences either in IgG to other viral proteins or in IgM between PRN and RP patients (Fig. 1c, e; Figs. S4, S5), suggesting that the humoral response to RBD rather than to other regions of the S protein or the full-length S protein might have played an important role in preventing viral rebound during recovery.