In other pneumonia model in C57BL/6 mice (Secher et al, 2011), the same monoclonal IgM KBPA101 could be detected in the bronchoalveolar lavage fluid of P. aeruginosa infected mice but not in uninfected animals, after the iv administration and, when it was given 4 h after the inoculation, decreased (1.5 log10 CFU) significantly the bacterial lungs concentration. This evidence concerns the gene CD40LG and pneumonia.