Recently, Nachbagauer et al. analyzed the cross-reactivity pattern of anti-HA Abs after an influenza infection in patients diagnosed with pH1N1/2009 or seasonal H3N2, and they found that a pH1N1 infection induces a broader response (against group 1 and group 2 HAs) than an H3N2 infection does. This evidence concerns the gene DDX41 and infection.