SPP1 and gastric cancer: Previous findings have found that SPP1 shows high expression in many cancers and can be used to predict patient prognosis, including ovarian cancer, glioblastoma, hepatocellular carcinoma and gastric cancer [41–43], but no studies have been shown to explore the relevance of SPP1 to LUAD,therefore our study may prove to SPP1 in LUAD and its potential clinical value.