When looking at the phosphorylation of GSK3β at Ser9, PCa showed a clear induction in mono- and co-cultured GBM cells after 3 and 6 days, respectively, whereas in PCb this effect was mainly detectable after 6 days of stimulation in mono-cultured cells and after both time points examined in co-cultured GBM cells. The gene discussed is GSK3B; the disease is glioblastoma.