A previous study by Ruiz et al. (2016) [12] using the LPAI virus infection of line C.B12 and line 0 demonstrated that line 0 birds were more resistant to infection and that the underlying mechanisms mediating greater resistance were not associated with higher adaptive immune responses, based on the levels of AIV-specific IFN-γ- and Ig-secreting cells in the spleen. This evidence concerns the gene IFNG and infection.