PBIT is a potent, cell-permeable inhibitor of Jumonji histone demethylase (JHDM). Innhibits JARID1B (also known as KDM5B or PLU1) with an IC₅₀ of about 3 μm in vitro. PBIT treatment inhibits removal of H3K4me3 by JARID1B in cells and inhibits proliferation of cells expressing higher levels of JARID1B.