Palmitoyl thioesterase that catalyzes depalmitoylation of CGAS and KCNMA1 (PubMed:22052940, PubMed:22399288, PubMed:37802025). Acts as a regulator of innate immunity by mediating depalmitoylation of CGAS, thereby preventing CGAS homodimerization and cyclic GMP-AMP synthase activity (PubMed:37802025). Does not exhibit phospholipase nor triacylglycerol lipase activity, able to hydrolyze only short chain substrates due to its shallow active site (PubMed:22052940).