KZR-261 is a Sec61 inhibitor that directly binds to the Sec61 channel, effectively impeding the synthesis of certain Sec61 client proteins. It exhibits broad anti-tumor activity, particularly against colorectal, pancreatic, and prostate cancers, activating the endoplasmic reticulum stress response while showing minimal adverse effects on normal cells. KZR-261 significantly induces apoptosis in H929 cells and effectively suppresses tumor growth in various xenograft mouse models, demonstrating good tolerability.