Although initial comparisons of rapamycin- and coibamide A-induced effects in U87-MG cells revealed increases in LC3-II and a pattern of MDC staining that were qualitatively similar, we found no evidence for inhibition of the mTOR pathway after analysis of the phosphorylation state of key residues on ULK1, p70 S6K1, S6 ribosomal protein and 4EBP-1, relative to starvation- and AZD8055-induced autophagy in human glioblastoma cells and MEFs. This evidence concerns the gene RPS6 and glioblastoma.