PROTAC CARM1 degrader-1 (compound 3b) serves as a highly potent degrader (DC50=8.1 nM) of the co-activator associated arginine methyltransferase (CARM1). This compound facilitates the degradation of CARM1 via the VHL-proteasome pathway. By degrading CARM1, PROTAC CARM1 degrader-1 effectively reduces the methylation of its substrates, including poly(A)-binding protein PABP1 and BGR1-associated factor BAF155, subsequently inhibiting breast cancer cell migration [1].