GDF15 and familial pancreatic carcinoma: To explore whether GDF-15 plays a biological role in pancreatic cancer tissues by means of GFRAL, we performed dual immunofluorescence staining assay to detect the localization of GDF-15 and GFRAL, and found that both protein molecules are co-expressed in pancreatic ductal epithelial cancer cells (Figure 5A–5P).