PROTAC LZK-IN-1 (Compound 21A) is a PROTAC that targets the degradation of LZK (Leucine Zipper Kinase, encoded by MAP3K13). PROTAC LZK-IN-1 (10 μM) promotes the degradation of LZK and inhibits the expression of p53 and c-MYC , leading to reduced viability of global head and neck squamous cell carcinoma (HNSCC) cell lines. PROTAC LZK-IN-1 can be used in cancer research. PROTAC LZK-IN-1 consists of an E3 ligase ligand (blue part,), a target protein ligand (red part,), and a linker (black part,).