Interestingly, inhibition of IRE1 reduces GBM growth in vivo (Drogat et al., 2007; Auf et al., 2010) but alters tumor cell migration/invasion properties (Dejeans et al., 2012; Jabouille et al., 2015), acting for instance on SPARC expression, a molecule associated with the extracellular matrix (Dejeans et al., 2012). This evidence concerns the gene ERN1 and glioblastoma.