Spearman’s correlation analysis illustrated that galectin-9 was strongly related to immune infiltration in COAD and READ (Table 2), especially for the five most significant infiltrators of immune cells, as follows: activated CD8 T cells (r = 0.231 in COAD, r = 0.276 in READ), central memory CD4 T cells (r = 0.203 in COAD, r = 0.138 in READ), CD56 bright NK cells (r = 0.216 in COAD, r = 0.245 in READ), activated DCs (r = 0.218 in COAD, r = 0.296 in READ), and type-1 T helper (Th1) cells (R = 0.116 in COAD, R = 0.219 in READ). This evidence concerns the gene LGALS9 and colon adenocarcinoma.