IL1B and congenital rubella syndrome: In the CAR group, 1 of 6 patients developed cytokine release syndrome (CRS) that required treatment with at least immunomodulation (IL1 or −6 inhibition) versus 9 of 12 patients in the 15.CAR group (relative risk 3.3, 95% confidence interval 1.226 to 9.723, p=0.043).