However, by 48 hrs post-infection, peribronchial and perivascular cellular infiltration into SP-D-/- lungs had decreased significantly (Fig. 7, arrows 1 & 2) but had increased in SP-D+/+ lungs as compared to SP-D-/- mice (Fig. 8, arrows 1 for cellular infiltration & arrows 2 for bronchial inflammation). This evidence concerns the gene SFTPD and infection.