To determine whether γ‐secretase‐mediated Fn14 proteolysis also occurs in primary human cells ex vivo, we analyzed primary cells obtained from tumor tissue of four different patients with glioblastoma (GBM) (Dong et al, 2015), where Fn14 expression is linked to poor patient survival (Tran et al, 2006; Perez et al, 2016; Hersh et al, 2018). Here, TNFRSF12A is linked to glioblastoma.