Smith SE, et al. - This paper incorporated an investigation of the sinonasal cytotoxic cells, their mediators, and cell-specific distribution of these mediators in patients with chronic rhinosinusitis with nasal polyp (CRSwNP) and in patients with chronic rhinosinusitis without nasal polyp (CRSsNP). A decrease was reported in the total levels of sinonasal granzyme B (GrB) and perforin, in the sinonasal mucosa of both the patients with CRSwNP and the patients with CRSsNP compared with the controls. In contrast, sinonasal CD8+ T cells, (but not natural killer (NK) cells), intracellular stores of GrB and perforin appeared to be reduced in the patients with CRSwNP compared with the controls.