IFNB1 and susceptibility to pneumonia measurement: In contrast, the levels of IFN-β were not significantly different between patients with and without pneumonia [5.6 pg/ml (2.1-7.5) vs 4.7 pg/ml (3.1-8.2), p = 0.488], but these were significantly higher in patients who developed hypoxemia than in those who did not [7.5 pg/ml (4.5-10) vs 4.5 pg/ml (1.8-6.3), p = 0.008].