For this purpose, the expression of the interleukin 2 (IL-2), IL-4, IL-6, IL-8, IL-10, interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) genes was investigated in Black and White (BW) Holstein and Gyr cows with and without clinical signs of mastitis. This evidence concerns the gene IL2 and mastitis.