Firstly, GEO profile GDS4468 shows the expression profiles of receptors in following glioblastoma cell lines (LN018, LN215, LN229, LN319 and BS149): human ACE2, AXL, and TMPRSS2 are widely expressed in these five cell lines; meanwhile, human DPP4, ANPEP, and ENPEP are highly distributed in BS149, followed by LN018, LN215, LN229, and LN319 (Figure 2A). This evidence concerns the gene DPP4 and glioblastoma.