PX-12 is an irreversible inhibitor of thioredoxin-1 (TRX-1) (Ki = 31 µM). It decreases the expression of HIF-1α, VEGF and iNOS (IC₅₀ values are 7.2, ~10 and 18.1 μM respectively). Also known to display antitumor activity and inhibits tubulin polymerization in vitro.