YBX1 and pancreatic ductal adenocarcinoma: For instance, the circRNA; circFOXK2, which was highly expressed in PDAC (pancreatic ductal adenocarcinoma) tissue samples, promoted the proliferation and invasion of PDAC cells by interacting with RBPs, YBX1 (Y-box binding protein 1), and hnRNPK (heterogeneous nuclear ribonucleoprotein K), to enhance the expression of oncogenes [17].