Taken together, these results allow classifying the analyzed genes into three groups: (1) genes that were regulated in response to mock treatment and infection in both strains (Retnla, Il6), (2) genes that were regulated in response to both mock treatment and infection in the DBA/2J strain only (Irg1, Cxcl10), and (3) those whose expression changed in response to infection only (Fos, Il1b, Stat1, Ifng, Ifnl2, and Mx1). This evidence concerns the gene IL6 and infection.