The biopsy pathology revealed a well-differentiated adenocarcinoma, and immunohistochemical analyses (Supplementary Figures S2A, B) demonstrated positive staining for CK20 and SATB2, a 90% Ki-67 labeling index, p53 positivity in a mutant pattern (≥70% of cells), and CEA positivity, all consistent with an adenocarcinoma phenotype. The gene discussed is SATB2; the disease is adenocarcinoma.