IFNA1 and susceptibility to pneumonia measurement: Causality between these AAN-I-IFN and lethal outcome of avian influenza in this patient is based on (1) our previous report that AA-I-IFN underlie about 5% of cases of critical pneumonia triggered by seasonal influenza viruses in three cohorts, (2) the rarity of this combination of AAN-I-FNs in individuals over 70 years old (<1%), and (3) the rarity of lethal avian influenza among infected individuals (<1%).