SPHK2 and cholangiocarcinoma: We aimed to investigate the potential antitumor effect of upamostat and opaganib, individually and in combination, on CCA patient-derived xenografts (PDX) in nude mice using PAX165, a cholangiocarcinoma PDX that expresses substantial levels of SPHK2, PRSS1, PRSS2, and PRSS3.