Subgroup analysis showed that XPF expression continued to be significantly up-regulated in cancer tissue in men (P < 0.001), women (P < 0.001), age > 60 (P < 0.001), age ≤ 60 (P < 0.001), colon cancer (P < 0.001), rectal cancer (P < 0.001) and other stratified analysis were meaningful (Table 2 and Fig. 2). The gene discussed is ERCC4; the disease is rectal cancer.