Expression of UCHL1, SNAT1, and EGR1 proteins was predominantly localized to the cytoplasm and was observed in 55.1% (27/49), 55.1% (27/49), and 44.9% (22/49) of hilar cholangiocarcinoma samples, respectively (Figure S6 and Table S3). Here, SLC38A1 is linked to hilar cholangiocarcinoma.