SPAG6 and clear cell renal carcinoma: Compared to non-malignant tissues we observed statistically significant downregulation of SPAG6 in breast carcinomas (p = 0.0039), colorectal carcinomas (p < 0.0001), head and neck carcinomas (p = 0.0030), kidney clear cell carcinomas (p < 0.0001) and in hepatocellular carcinomas (p = 0.0046), but not in prostate carcinomas (Additional file 2: Figure S1).