Our results are consistent with previous studies (9, 19), in which transcriptome analysis showed that infection of porcine alveolar macrophages with the virulent genotype II strain HLJ/18 (MOI = 1) or the attenuated HuB20 (MOI = 3) resulted in increased expression of cytokine-related genes and ISGs, including MX1, as well as the transcription factor STAT1 (9, 19). This evidence concerns the gene STAT1 and infection.