PBIT is a specific inhibitor of the Jumonji AT-rich Interactive Domain 1 (JARID1) enzymes. PBIT inhibits JARID1B (KDM5B or PLU1) histone demethylase with an IC50 of about 3 μM . PBIT also inhibits JARID1A and JARID1C with IC50 s of 6 and 4.9 μM, respectively.