ID2 and esophageal squamous cell carcinoma: Moreover, high level of both nuclear and cytoplasmic expression of Id-2 provides favourable prognosis for our ESCC patients, with mean survival of 28.9 (95% CI: 16.7–41.1) months when compared to those having low overall Id-2 expression (16.8 (95% CI: 12.3–21.1) months).