IL18 and Keratoconjunctivitis sicca: Previous studies found that the expressions of nucleotide-binding oligomerization domain-like receptor family pyrin domain containing three (NLRP3) inflammasome and its downstream inflammatory factors—caspase-1, IL-1β, and IL-18 were upregulated in dry eye patients (43) and in desiccating stress-induced murine dry eye models (44).