Thus, these data provide further evidence for IL-5, IL-6, IL-8, IFN-γ, TNF, and comorbidities including asthma, polyposis, and aspirin sensitivity, in addition to the previously identified IL-13, albumin, myeloperoxidase, eosinophilic cationic protein, IgE, and SE-IgE (10, 11), as important variables in efforts to demarcate distinct endotypes of CRS. Here, MPO is linked to congenital rubella syndrome.