ATF4 and glioma: In leukemic cells, ceramide can induce apoptosis by regulation of p38 MAPK (mitogen-activated protein kinase) signaling, while in glioma cells it up-regulates the endoplasmic reticulum (ER) stress-related gene, those encoding the transcription factors activating transcription factor 4 (ATF-4) and C/EBP homologous protein (CHOP), and the stress-related pseudokinase [7] (Figure 1).