Immunofluorescent analysis of GSC‐derived orthotopic GBMs showed that the CD146+ pericytes were partly stained with CD44, whereas pericytes in normal brain tissues from tumor‐bearing mice barely had CD44 staining (Figure7A,B), indicating that a CD44High pericyte subpopulation existed in GBM xenografts but not brain tissues. Here, CD44 is linked to neoplasm.