As the results shown in Additional file 1: Table S1, except for TP53, the remaining six IBDGs expression exhibited significant positive correlation with the infiltration of multiple immune cells in colon (COAD) and rectal tumors (READ), such as B cells, CD8 + T cells, CD4 + T cells, macrophages, neutrophils or dendritic cells. Here, CD4 is linked to rectal neoplasm.