First, we performed differential expression analysis of 38 genes in the HOX gene family, and the results showed that compared with normal colon tissues, there were 15 genes whose expression was significantly upregulated (HOXA3, HOXA9, HOXA10, HOXA11, HOXB3, HOXB4, HOXB5, HOXB6, HOXB7, HOXB9, HOXC5, HOXC6, HOXC9, HOXC10, HOXC11) (Figures 1A, D, E and S1) and nine genes whose expression was significantly downregulated in tumor tissues (HOXA5, HOXA6, HOXA13, HOXC4, HOXD1, HOXD3, HOXD4, HOXD8, HOXD9) (Figures 1C, I–K, and S2). The gene discussed is HOXD9; the disease is neoplasm.