AKT1 and glioblastoma: In addition, sst5TMD4 overexpression induced an increase in the phosphorylation levels of several proteins belonging to the AKT pathway in both GBM cell models (Figure 3A), including AKT1, BAD, EIF4EBP1, P70S6K, and PDK1, as well as an increase in GSK3A, CDKN1B, and PRASA40 only in U-87 MG (Figure 3B,C,E).