MTH2 can generate ARGO cleavage–induced luminescence. A, Comparison of ARGO cleavage–generated luminescence in response to increasing concentrations of human recombinant MTH1 and MTH2, up to 5 nmol/L. Each concentration was run in triplicate. Error bars, ± SD. B, Comparison of ARGO cleavage–generated luminescence in response to increasing concentrations of human recombinant MTH1 and MTH2 (up to 1 μM/L). Each concentration was run in triplicate. The boxed lines indicate the concentrations of MTH1 versus MTH2 at which equivalent ARGO cleavage–induced luminescence is observed. Error bars, ± SD.