In addition, infiltrating cells including c-kit+ mast cells, CD68+ macrophages, myeloperoxidase+ neutrophils, and CD20+ B cells also had MEX3B expression in mucosa from patients with CRS (Supplemental Figure 1; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.159058DS1). Here, MEX3B is linked to congenital rubella syndrome.