The modern history of IPF-AEs begins probably in 1993 when Yashuhiro Kondoh reported a case series of three patients with IPF fulfilling ARDS criteria including PaO2/FiO2 ≤ 300, presenting with “influenza-like symptoms and/or cough and fever; leukocytosis and high CRP; with biopsy proven, at least in two of them; and UIP histology and acute lung injury (ALI)” (Kondoh et al., 1993). Here, CRP is linked to acute lung injury.