PIK3CA and cholangiocarcinoma: In a clinical study, selumetinib (selective MEK 1/2 inhibitor) has a synergistic effect with gemcitabine and cisplatin in advanced CCA and ongoing clinical trials (NCT02042443, NCT01438554) [124]; (4) The combined treatment of CCA includes the PI3K/AKT/mTOR pathway (BKM120), the RAF–MEK–ERK axis with gemcitabine and platinum-based drugs [125]; (5) Tissue with abnormal expression of mesothelin in several malignant tumors has been observed.