From our investigations we have shown that the sinonasal cell line RPMI 2650 is significantly different from patient-derived PNECs in terms of its cellular morphology, surface marker expression, and biological response to CRS disease-relevant inflammatory ligands such as TNF-α.22, , -25 While this is initially disappointing, it is perhaps not surprising when we investigate the origin of the cell line. Here, TNF is linked to congenital rubella syndrome.