Additionally, although the highest methylation of HOXA5, HOXA2, and HOXA6 occurs in early stages of colorectal cancer tissues, methylation level at any stage of the tumor was still significantly higher than in normal tissues, which indicate HOXA5, HOXA2, and HOXA6 may be involved in the progression of colorectal cancer. This evidence concerns the gene HOXA2 and colorectal cancer.