SRC and glioblastoma: To test the potential role of P4 in cSrc activation in glioblastoma cells, at the beginning of the study, a time-dependence assay (0–60 min) using P4 (10 nM) was performed in U251 cells (Supplementary Figure 1), however, a significant effect on p-cSrc/cSrc ratio was not observed, and we decided to test higher P4 concentrations, at 10 (Figures 1A, B) and 15 min (Supplementary Figure 2).