ETS1 and glioma: To more specifically dissect the link between MAPK-signaling and telomerase re-activation, we applied siRNA mediated knock-down of ETS1. Knock-down consistently decreased TERT mRNA expression across BRAFV600E/TERT promoter-mutated glioma cells as well as in a TERT promoter-mutated cell model (Fig. 5a).