SPOP and neoplasm: Similarly, although the difference had no statistical significance, in consideration of RR value, larger tumor size (RR 1.30, 95% CI 0.67–2.54, I2  = 90%, random effect model, 6 comparisons, 480 cases), more positive lymph node metastasis (RR 1.94, 95% CI 0.86–4.36, I2  = 89%, random effect model, 5 comparisons, 480 cases) and distant metastasis (RR 1.30, 95% CI 0.54–3.15, I2  = 92%, random effect model, 5 comparisons, 323 cases) showed reduced expression level of SPOP (Fig. 3).