GZMB and glioblastoma: To study the potential role of Talpha1 in enhancing T cell-mediated killing of 9L glioblastoma cells, we constructed an in vitro assay in which Talpha1- or vehicle-treated 9L cells were incubated with Granzyme B in the presence or absence of Streptolysin O (permeabilizing agent) for 1 or 3 hours.