NANOGP8 and glioblastoma: Single Nucleotide Polymorphism (SNP) in exosomal SOX2: The PCR product sequences of SH-SY5Y, GBM and CD133+ GBM derived exosomes when compared to that of NSC derived exosomes or the NCBI reported SOX2 gene sequence did not reveal obvious differences such as insertions/deletions of multiple nucleotide or DNA fragments as found in NANOG and NANOGP8 [10].