ML348 is a competitive and reversible inhibitor of acyl palmitoyl thio-esterase 1 (APT1 – an enzyme encoded by the lysopholipase 1 gene (LYPLA1)). With a Ki = 300nM and an IC50 = 840nM, it exhibits a 14 fold greater selectivity for APT1 over APT2 (Ki and IC50 > 10µM).