Though we were not able to distinguish the different ceramide species in tumor specimen, we used the MS analyses of the respective tumor cells and EC, as well as fibroblasts being either CAV1-proficient or -deficient to mimic the human situation with respect to the differential CAV1 levels being characteristic for low-grade tumors and advanced tumor stages (Supplemental Fig. 6). This evidence concerns the gene CAV1 and neoplasm.