To determine whether GPIHBP1 is expressed in a mouse model of glioblastoma, spheroids of syngeneic C57BL/6 mouse CT-2A glioma cells (Seyfried et al., 1992; Oh et al., 2014), modified to express a blue fluorescent protein (BFP) (Mathivet et al., 2017), were engrafted into the brains of mice harboring an endothelial cell–specific Pdgfb-iCreERT2 transgene (Claxton et al., 2008) and a ROSAmT/mG reporter allele (Muzumdar et al., 2007). The gene discussed is PDGFB; the disease is central nervous system cancer.