– QZ2135 (compound 20) is a PROTAC degrader that specifically targets RET and exhibits antitumor activity in vivo within a Ba/F3-KIF5B-RET-G810C xenograft mouse model. The compound demonstrates degradation activity with DC50 values of 4.7 nM (WT), 17.2 nM (V804M), and 73.8 nM (G810C) when targeting KIF5B-RET. QZ2135 is composed of the target protein ligand (red part) RETligand-3, the E3 ligase ligand (blue part) Lenalidomide-F, and the PROTAC Linker (black part) 7-Iodohept-1-yne, wherein the target protein ligand combined with the linker forms the conjugate RETLigand-Linker Conjugate-1.