IL4 and congenital rubella syndrome: Thus far, the most common endotypes of CRS are classified as type 1, type 2, or type 3 immune responses based on innate and adaptive cell‐mediated effector immunity, and the representative Th cytokines in these immune responses, such as IFN‐γ, TNF‐α, IL‐4, IL‐5, IL‐13, IL‐10, IL‐17, and IL‐22, play an important regulatory role in mucin secretion.