Of the nine immune-related genes analyzed individually using RT-qPCR (MHC I-uka, MHC II-dab, FGG, IRGF1, C7, CXCL11.8, CD4-1, LECT2, and AHSA1B), five displayed significant differences either in expression between lines (MHC II-dab, P = 0.013; IRFG1, P = 0.037), infection status (FGG, P = 0.034), or both (CD4-1 line, P = 0.048, infection P = 0.011; CXCL11.8, line P = 0.0025, infection P = 0.016) (fig. 2). This evidence concerns the gene ITGA2B and infection.