ARID1A and intrahepatic cholangiocarcinoma: A further limitation was the 50 cancer gene panel used for targeted sequencing, as it only covered hotspot mutations in the 50 genes most commonly mutated in a broad range of cancers (listed in Supplementary Table S5), whereas the use of a comprehensive and specific upper GI cancer panel, including genes associated with recurrent mutations in ICC such as ARID1A and BAP1 [9], may provide genetic profiling more specific to ICCs.