GSK_WRN3 acts as a selective inhibitor of the WRN protease with an IC 50 of 8.6 μM. It demonstrates significant selectivity by covalently binding to the Cys727 residue of the WRN protein. By inhibiting WRN protease activity, GSK_WRN3 hinders the growth of MSI tumor cells by increasing DNA double-strand breaks and inhibiting cell proliferation [1].