KRAS and cholangiocarcinoma: Thus, more functional inhibitors have been designed for tumorigenesis: (1) The PKA inhibitor isoquinoline H89 can inhibit CCA cell proliferation by regulating the expression levels of PRKACA and PRKACB [121]; (2) S63845 and AZD1480 can regulate myeloid cell leukemia sequence 1 (Mcl-1), Janus kinase (JAK) and the signal transducer and activator of transcription (STAT) signaling cascade [122,123]; (3) KRAS is a typical mutant marker in CCA.