The combined results from fat-1-APCMin/+ mice, CRC cell lines (SW480 and HCT116), and NCM460 cells with silenced APC revealed that elevated n−3/n−6 PUFAs ratio through either intracellular conversion of n−6 to n−3, or through n−3 supplementation, can significantly repress the proliferation and promote apoptosis in colorectal cancer cells, and inhibit the formation of intestinal adenomas, thereby preventing the development of colorectal cancer, as well as the accompanying anemia. The gene discussed is FAT1; the disease is anemia.