Cambinol (SIRT1/2 Inhibitor IV) is a cell-permeable b-naphthol compound that inhibits the NAD-dependent deacetylase activity of SIRT1/2 (IC50: 56/59 μM, respectively) in a substrate-, but not NAD-, competitive manner. Cambinol inhibits SIRT5 deacetylase activity only at much higher concentrations (IC50 >300 μM) and no inhibitory for the class I and II HDACs. In BCL6-expressing Burkitt lymphoma cell lines, Cambinol-induced apoptosis has been attributed to the hyperacetylation of p53 and BCL6.Cambinol is a potent brain penetrant neutral sphingomyelinase (N-SMase) inhibitor (exosome inhibitor)