We also detected a weak positive correlation between disease activity scores, being the Harvey-Bradshaw index for CD and Simple Clinical Colitis Activity Score for UC, and normalized proportions of TcdB-specific CD4+ T cells, indicating that milder symptoms were associated with a reduced proportion of memory TcdB-specific CD4+ T cells in peripheral blood (r = 0.427, P = .0047) (Figure 1C). This evidence concerns the gene CD4 and colitis.