Two weeks post-tumor cell inoculation, the rats received a non-fluorescent diet (Purified Mouse Diet, MP Biomedicals, LLC, Illkirch, France) to reduce auto-fluorescence from chlorophyll contained in regular chow. Three to 4 weeks post-tumor inoculation, rats were randomly divided into 10 experimental groups to either receive different doses of ABY-029 (24.5, 49.0, or 122.5 μg/kg) at different time points (1–48 h) or PBS (control group). The lowest dose, 24.5 μg/kg, corresponds to the human equivalent microdose for a protein molecule, defined by the FDA as ≤30 nanomoles (Guidance for Industry, Investigators, and Reviewers-Exploratory IND Studies, 2006). After the predetermined time, the animals were euthanized by cervical dislocation; the brain was removed and sectioned into 2-mm thick slices. Three U251 inoculated rats and two sham rats, for each group, were used.