– CCT367766 formic is a potent third-generation heterobifunctional Cereblon-based protein degradation probe (PDP, or PROTAC) that selectively targets pirin for degradation, effectively diminishing its protein expression at low concentrations. This compound demonstrates moderate affinity towards the CRBN-DDB1 complex, as denoted by an IC50 value of 490 nM, while exhibiting strong binding to recombinant pirin and CRBN, with respective Kd values of 55 nM and 120 nM. As such, CCT367766 formic serves as a valuable chemical probe for investigating the functions of the largely unexplored pirin protein [1].