CBLN1 and glioma: The ability of the PI3K/Akt pathway to be regulated by/to regulate sphingolipid metabolism may be pathologically relevant in gliomas if we consider that the more malignant phenotypes of these tumors are associated with the up-regulation of the PI3K/Akt pathway [56,57], increased amounts of SM [62] of glucosylceramide [63], and low Cer levels [25].