PIWIL1 and neoplasm: As for clinicopathological characteristics, the results suggested that PIWIL1 overexpression had no obvious relationship with age, gender, tumor size, differentiation, and distant metastasis, but was significantly associated with deeper tumor invasion (n = 5, OR = 2.26, 95% CI: 1.09–4.70, p=0.03), higher clinical stage (n = 6, OR = 1.53, 95% CI: 1.09–2.14, p=0.01), and more lymph node metastasis (n = 4, OR = 1.90, 95% CI: 1.25–2.88, p=0.003).