APAF1 and glioblastoma: Loss of mitochondrial membrane potential (ΔΨm) activates caspase‐mediated apoptosis through the release of cytochrome C and apoptotic protease activating factor 1 (APAF1) from mitochondria.49 Jeon et al23 demonstrated that imipramine triggered autophagic cell death (type II programmed cell death) in glioblastoma U‐87 MG cells.