The results of Spearman's rank correlation coefficient indicated that the relationship between pO2 levels and the protein levels of HIF-1 alpha and CK20 was strongly negatively related in CRC tissues (Rho = −0.72 and −0.69, resp., P < 0.05) (Figures 6(b) and 6(c)). This evidence concerns the gene KRT20 and colorectal carcinoma.