POP1 (Processing of Precursor 1) is a multifunctional protein with distinct roles in RNA processing and inflammatory regulation. As a component of ribonuclease P and MRP complexes, POP1 participates in generating mature tRNA molecules by cleaving 5'-leader sequences and processing pre-rRNA 123. However, POP1's primary clinical relevance stems from its role as a negative regulator of inflammasome formation. POP1 contains a pyrin domain (PYD) that directly binds ASC via homotypic PYD:PYD interactions, competitively blocking ASC recruitment to NLRP3 and preventing inflammasome assembly 45. This inhibitory mechanism dampens caspase-1 activation and reduces IL-1β/IL-18 secretion. POP1 expression is therapeutically relevant in inflammatory diseases: it ameliorates monosodium urate crystal-induced gout by reducing neutrophil infiltration and inflammatory cytokines 6, and PGC-1α upregulates POP1 to suppress NLRP3 signaling in lipopolysaccharide-treated periodontal stem cells 7. Conversely, elevated POP1 expression promotes breast cancer progression through telomerase stabilization and telomere maintenance 89. Biallelic POP1 mutations cause anauxetic dysplasia, while rare variants expand the phenotypic spectrum to include developmental delay and congenital malformations 10.