As shown in Fig. 2A, the average absorbance ± SD for anti-Fn-IgA in CRC groups and its stage I-II of CRC groups was 0.390 ± 0.215, 0.367 ± 0.163, respectively; while in healthy controls and benign colon disease group was 0.246 ± 0.132, 0.268 ± 0.158 respectively. The gene discussed is FN1; the disease is colorectal carcinoma.