In addition, the peak cytokine (IL-6 and IFN-γ) levels in the PTR group were higher than those in Non-PTR group, and CCI was negatively correlated with the serum cytokine IL-6 levels, implying that IL-6 contributed to CRS and was the more important factor resulting in PTR. The gene discussed is IFNG; the disease is congenital rubella syndrome.