Serial sections of tumor sites were examined by hematoxylin-eosin staining and immunohistochemical analysis of pAKT, phosphorylated glycogen synthase kinase–3β (pGSK-3β, with phosphorylation of GSK-3β being mediated by AKT in the PI3K-AKT pathway), CD31 (a marker of vascular endothelial cells), and proliferating cell nuclear antigen (PCNA) (S2E–S2N Fig). The gene discussed is PECAM1; the disease is neoplasm.