YAP1 and gastric cancer: As the gene locus of YAP is frequently amplified in various human cancers [25, 36, 37], the elevated expression of YAP has been consistently observed in multiple types of human cancers, for example non-small-cell lung cancer (NSCLC) [38, 39], gastric cancer [40, 41], urothelial carcinoma of the bladder (UCB) [42, 43], esophageal squamous cell carcinoma (ESCC) [44, 45], ovarian cancer [46, 47], CRC [48, 49], and cervical cancer [50, 51].