To assess the impact of disruption of the CBFβ gene in the myeloid lineage we examined the outcome of intranasal (i.n.)infection of CBFβΔLysM mice and wild type (WT) control CBFβfl/fl littermates with a sublethal dose (0.1LD50) of the mouse adapted Influenza A strain A/PR/8 [H1N1]. The gene discussed is CBFB; the disease is infection.