GDF15 and malignant colon neoplasm: The main marker genes are DUOX2 [33], OLFM4 [45], MUC2 [10], DEFA6 [14], MKI67, GDF15 [40], SELENBP1 [46], IGLC1 (no related study with colon cancer has been reported), CA1 [47], CHGA [48], and GCG [28].