DDIT3 and neoplasm: Maternally expressed gene 3 (MEG3) inhibits miRNA (miR)-103a-3p, upregulates PDHB-induced endoplasmic reticulum stress proteins’ expressions (glucose-regulated protein 78 (GRP78), activating transcription factor 6 (ATF6), C/EBP homologous protein (CHOP), caspase-3, and caspase-9), inhibits cell viability, colony formation ability and invasion, blocks the cell cycle, and induces apoptosis in tumor cells (30).