By contrast to tumours expressing only membranous CD9, the 23 tumours with both membranous and cytoplasmic staining showed a trend toward significant association with tumour stage (P=0.08) (95% CI 3.5–86) and disease failure (P=0.083) (95% CI −1.7–57), while the association with tumour grade (G1 vs G2–3) was less strong (P=0.025 vs 0.0006) (95% CIs 11–68 vs 10–37). This evidence concerns the gene CD9 and neoplasm.