(A, B) CLR1502 fluorescence of 22 GSC-derived orthotopic xenograft (B) compared to visible light (A). (C, D) CLR1502 fluorescence of 22 GSC-derived xenograft demonstrating excellent macroscopic tumor delineation from normal brain (D), compared to visible light (C). (E, F) Verification of tumor (E) and normal brain (F) by histology (H&E). T: tumor, N: normal brain.