Three out of five cell lines tested, mel Il, mel Mtp and HDF, expressed IFN-β mRNA at different levels inducing at 24 h post infection and decreasing with time of cultivation, while two cell lines did not express IFN-β mRNA (mel Z cells) or expressed it at a statistically non-significant level (mel Ibr cells, p > 0.05). Here, IFNB1 is linked to infection.