IL-6 levels in milk from HE cows ranged from 6.09–80.24 pg/mL (median 26.6 pg/mL) and were significantly lower than in milk from both cows with clinical and subclinical mastitis (487.09 pg/mL vs. 26.6 pg/mL in CM, p < 0.001; and 165.31 pg/mL vs. 26.6 pg/mL in SCM, p < 0.001). This evidence concerns the gene IL6 and mastitis.