NLRP3 and infection: Interestingly, whereas it is widely accepted that NLRP3 is primarily expressed in immune cells (e.g., monocytes and macrophages), multiple studies suggest that very low levels of NLRP3 may be present in a variety of tissues [15] including neurons [16], islets [17], and retinal cells [18, 19], providing a localized response to infection and/or stress.