Importantly, a statistically significant interaction was observed between stage and SOX2 gene status (P = 0.021), indicating that the prognostic impact of increased SOX2 gene copy number differed according to tumor stage and was limited to patients with early stage disease (HR 0.44, 95% CI: 0.25–0.77; P = 0.004, adjusted for histology). The gene discussed is SOX2; the disease is neoplasm.