YAP1 and gastric neoplasm: Furthermore, immunohistochemistry of tumor sections revealed significantly higher expression of cleaved caspase 3 in gastric tumors of Gp130FF; Yap1KO mice when compared with Gp130FF; Yap1WT mice (Fig 4I), confirming a clear up-regulation of multiple pathways that enhance apoptosis in response to Yap1 gene ablation.