(R)-NX-2127 ((R)-compound 28) is an isomer of the BTK PROTAC degrader NX-2127. (R)-NX-2127 is composed of PROTAC target protein ligand (red part) BTK ligand 10 , E3 ligase ligand (blue part) Thalidomide 5-fluoride and PROTAC Linker (black part) Thalidomide-pyrrolidine-C-piperidine-Ph-NH2.