The genes and their variants linked to differences in fatty acid absorption include fatty acid desaturase genes (FADS1, FADS2), the peroxisome proliferator-activated receptor genes (PPARA, PPARG), the X-ray repair cross-complementing protein 1 gene (XRCC1) and stearoyl-CoA desaturase (SCD1). A number of studies have discussed the role that these genes play in the serum levels of LC-PUFA-omega-3 and omega-6 fatty acids, as well as the effects of various variants on metabolic pathways and how this impacts inflammation and cancer risk [94,95,96,97,98,99,100,101,102,103,104]. Here, XRCC1 is linked to cancer.