However, higher CD133 expression level was associated with poor/moderate differentiation (OR = 2.03, 95% CI: 1.32–3.14, p = 0.001; I2 = 54.8%, p = 0.007), lymph node metastasis (OR = 2.39, 95% CI: 1.62–3.52, p < 0.001; I2 = 61.5%, p = 0.001) and histological type (OR = 1.21, 95% CI: 1.01–1.46, p = 0.041; I2 = 21.8%, p = 0.18) (detailed forest plot figures see Supplementary Figure S9–S11 in Supplementary Material). This evidence concerns the gene PROM1 and metastatic malignant neoplasm in the lymph nodes.