We observed an increase in the concentration of arachidonic acid (AA) derivatives synthesized via the cyclooxygenase (COX) pathway, a decrease in the concentration of metabolites synthesized via the epoxygenase pathway (AA and linoleic acid (LA) metabolites), lipoxygenase (LOX) pathway (DHA metabolites), and a decrease in the concentration of endogenous cannabinoid Anandamide (AEA) in the blood of BC patients. This evidence concerns the gene LOX and breast cancer.