CD40 and congenital rubella syndrome: It is worth to mention that preclinical studies and clinical trials with FcγR- and C1q-interacting anti-CD40 antibodies give evidence for significant dose limiting toxicity (cytokine release syndrome (CRS), hepatotoxicity) [2,3,21–23], while clinical studies with anti-CD40 antibodies lacking Fc effector functions showed excellent tolerability [24–27].