PDI inhibitor 16F16 is a protein disulfide isomerase (PDI) inhibitor, first identified in a screen for compounds that prevent apoptosis induced by mutant huntingtin protein. 16F16 not only suppressed apoptosis induced by the misfolded protein mutant hungtingtin, it also protected rat neurons from cell death triggered by Aβ peptide. The actions of this inhibitor helped to identify a new mechanism in which a cell death pathway is regulated by protein misfolding via PDI upregulation. [[922507-80-0]]