TWIST1 and pancreatic ductal adenocarcinoma: Using similar genetically engineered mouse models (GEMMs) of pancreatic ductal adenocarcinoma (PDAC), we previously reported that genetic deletion of Snai1 (Snail) or Twist1 (Twist) was dispensable for the formation of metastases but reduced chemoresistance (Zheng et al, 2015).