MMP9 and familial pancreatic carcinoma: A fundamental study showed that ARHGAP4 is a novel regulatory factor of the HDAC2/β-catenin pathway, which inhibits β-catenin activation by interacting with and ubiquitinating HDAC2, and regulates cell invasion and migration of pancreatic cancer as well as the downstream effectors MMP2 and MMP9 expression in vitro (Shen et al., 2019).