In accordance, infection models in PAI-1 knockout mice have shown that PAI-1 is protective in defense against sepsis caused by Klebsiella pneumoniae, Burkholderia pseudomallei, and Y. enterocolitica (Renckens et al., 2007; Hua et al., 2011; Kager et al., 2011; Luo et al., 2011) and lung infections by Haemophilus influenzae and P. aeruginosa (Goolaerts et al., 2011; Lim et al., 2011). Here, SERPINE1 is linked to infection.