IL6 and congenital rubella syndrome: In patients with lymphoid malignancies developing severe CRS after treatment with CD19-directed CAR-T cells such as tisagenlecleucel or the bispecific T-cell engager blinatumomab, blocking IL6 signaling by using a monoclonal antibody to the IL6 receptor (e.g., tocilizumab and siltuximab) was highly effective leading to a rapid resolution of the CRS (Teachey et al., 2013; Davila et al., 2014; Maude et al., 2014; Khadka et al., 2019).