Hes1 is essential in proliferating

Intrahepatic cholangiocarcinoma (ICC), which is frequently driven by aberrant KRAS activation, develops in the liver. Although Notch signaling pathway is a critical pathway involved in ICC development, detailed mechanisms of Notch-driven ICC development are still unknown. Here, using mice whose Notch signaling is genetically engineered, we examined whether the Notch signaling pathway, especially the Notch/Hes1 axis, plays an essential role in expanding ductular cells in the liver with chronic inflammation and/or oncogenic Kras activation.