These results are in line with studies showing the involvement of other extracellular matrix proteins, such as type 1 collagen and fibronectin in cancer cell biology, where they activate intracellular signaling pathways.42, 43, 44 Our findings that Ogn expression is upregulated by C/EBPβ LIP and CHOP are in line with a study demonstrating induction of Ogn mRNA expression by UV irradiation, as UV triggers ER stress.21 p53 was reported to activate the Ogn promoter.21, 22, 45 Our finding that p53 had no effect on Ogn mRNA and protein expression is in contrast to this report. This evidence concerns the gene DDIT3 and cancer.