Histologically, KD-fed AcinarKrasG12V mice developed invasive, sarcomatoid-like pancreatic ductal adenocarcinoma (PDAC), whereas HFD-fed mice showed increased poorly differentiated PDAC; in both groups, these aggressive tumors were associated with extensive fibrosis and increased stromal CD39 expression relative to tumor compartments. The gene discussed is ENTPD1; the disease is neoplasm.