(S,R)-CFT8634 (compound 176) is a selective and orally active PROTAC-class BRD9 protein degrader. (S,R)-CFT8634 has the potential to study BRD9-mediated diseases, including but not limited to abnormal cell proliferation. (S,R)-CFT8634 consists of a target protein ligand (red part) BRD9 ligand-5 , an E3 ligase ligand (blue part) CRBN ligand-11 , and a PROTAC linker (black part) 1-(3,3-Difluoro-4-piperidinyl)piperazine. E3 ligase ligand and linker can form E3 Ligase Ligand-linker Conjugate 142.