PROM1 and central nervous system cancer: It will be challenging, but orthotopic GBM brain tumors underneath the intact skin and skull have recently been unambiguously visualized using the enhanced NIR fluorescent protein IFP2.0.35 In addition, Jing et al. have reported that CD133‐IR700DX mAb‐based NIR‐PIT extended the overall survival of mice with patient‐derived orthotopic gliomas by a factor of two when light was applied through the skull following i.v. administration of the conjugate.36