The reasons for patient exclusion were: 5 had underlying conditions (e.g. cerebral palsy, alpha-1-antitrypsin deficiency, hepatitis A, and congenital cystic adenomatoid malformation), and 3 had a clinical history incompatible with pneumonia (i.e. respiratory symptoms on hospital admission were better accounted for by conditions such as severe reactive airway disease, croup, or aspiration). Here, PSMA6 is linked to susceptibility to pneumonia measurement.