We also identified frequent focal deletions at 3p12 harboring ROBO1 and ROBO2, one of which accompanies a nonsense mutation of ROBO1. Aberration of SLIT/ROBO signaling has been recently identified in other gastrointestinal tumors [14] suggestive of its potential oncogenic roles in ICC pathogenesis. The gene discussed is ROBO2; the disease is intrahepatic cholangiocarcinoma.