RA375 is a RPN13 (26S proteasome regulatory subunit) inhibitor. RA375 activates UPR signaling, ROS production and apoptosis. RA375 exhibits ten-fold greater activity against cancer lines than RA190, reflecting its nitro ring substituents and the addition of a chloroacetamide warhead.In Vivo: RA375 (10 mg/kg, ip) inhibits proteasome function and reduces ovarian tumor burden in mice.