PROTAC BRD4 Degrader-13 (compound 9d) is a von Hippel-Lindau system-based PROTAC BRD4 degrader with a linker that can be coupled to ADC antibodies to form PACs (PROTAC-antibody Conjugates). PROTAC BRD4 Degrader-13 can be coupled to STEAP1 and CLL1 antibodies to degrade BRD4 protein in PC3 prostate cancer cells with DC 50 values of 0.025 nM and 6.0 nM, respectively.