GNAS and medulloblastoma: We also tested NESP55 expression under anaerobic conditions in the human medulloblastoma cell line D324 Med and in the human supratentorial PNET cell line PFSK1 indicating insignificant (1.2-fold; standard error of mean .035) or minor (2.4-fold; standard error of mean .178; p<.001) induction, respectively.