SPHK1 and glioblastoma: A recent study by Van Brocklyn et al. demonstrated in Kaplan-Meier survival analysis that expression of SphK1 is associated with the outcome of GBM patients [33] but such a relation between patient's survival and SphK1 expression was not detectable in our patient cohort despite an elevated expression of SphK1 in the investigated GBM specimens.