Thus, some epidemiological studies have shown that high serum concentrations of oleic acid together with low levels of stearic acid (high SCD-18 desaturation index) [46,47], as well as high levels of palmitoleic acid to the detriment of palmitic acid concentrations (high SCD-16 index) [18,43,44]—both indicators of high SCD-1 activity—are associated with an increased BC risk. The gene discussed is SCD; the disease is breast cancer.