Fig. S3A–C showed that the OD value of anti-B. fragilis, anti-E. coli and anti-E. cloacae-IgA or -IgG were too low to be detected when applied diluted sera (1:1000 for anti-IgA or 1:4000 for anti-IgG level detection) from both patients and controls. Though the level of anti-E. Faecalis-IgA or -IgG were much higher than the other three bacterial strains, it showed no significant difference between CRC and two control groups (Fig. S3D). Here, CD79A is linked to colorectal carcinoma.