ADGRG1 and glioblastoma: However, when we reassessed the mRNA expression of GPR56 by qRT-PCR in multiple GBM biopsy specimens (n=28) and at the protein level using immunohistochemistry (IHC) on a commercial tissue microarray (n=27), we found expression of GPR56 to be heterogeneous across specimens (Figures 1A–C and Supplementary Tables 1, 2).