BRD4 degrader-2 (Compound JP-2-197) is a covalent monovalent molecular glue BRD4 degrader that induces a ternary complex formation between BRD4 and RNF126. BRD4 degrader-2 targets RNF126 (E3 ligase ) and degrades both the long and short isoforms of BRD4 in cells.