P4HB and gastric cancer: It has been reported that P4HB is indicated as a diagnosis and prognosis biomarker and the abnormal higher expression of total P4HB protein level has been found in various tumor types, such as renal cell carcinoma (41), bladder carcinoma (24), gastric cancer (42), diffuse gliomas (43), lung cancer (44), and hepatocellular carcinoma (45).