gGlu-HMRG probe activation at SHIN3 tumors. (A) Representative white light and fluorescence images of SHIN3 tumors for each group (representative of four SHIN3 tumors per group) before and 1, 10, 20, 30, 40, 50, and 60 min after gGlu-HMRG administration. (B) Changes in tumor fluorescence signals in SHIN3 tumors (n = 4 per group). Data are mean fluorescence intensities (a.u.) ± SEM of tumors at different time points.