Calus L, et al. - Chronic rhinosinusitis with nasal polyposis (CRSwNP) is an inflammatory disease associated with lymphoid aggregates and local IgE production related to Staphylococcus aureus enterotoxins. A crucial role of T-follicular helper cells and their effector cytokine interleukin (IL)-21 in germinal center proliferation has been reported. In this study, it was demonstrated that patients with CRSwNP had increased IL-21- and IL-21-producing CD4+ T cells. Additionally, S. aureus can modulate the function of Tfh cells in nasal polyps as indicated by the observed SEB-induced increase in IL-21 and IL-21+CD4+ T cells. It was speculated that T-follicular helper cells and IL-21 are important in the pathophysiology of CRSwNP.