The mean renal cancer distribution and the normal group distribution are approximately equal for most of the genes in Fig. 1, indicating that the linear relationship is nearly zero (for example, ADAMTS13, APOE, BMP4, GFRA1, RCOR1, SEC63, SIRT1, Pearson R’s p value > 0.05 in Table 4). This evidence concerns the gene BMP4 and renal carcinoma.