OAS1 and susceptibility to pneumonia measurement: Consistent with the lack of pneumonia in these patients, no increase in SARS-CoV-2 susceptibility was observed in any of the fibroblasts with OAS1 (from P1), OAS2 (P3 and P4), or RNASEL (P5) mutations up to 72 hours after infection in the presence or absence of exogenous IFN-α2b, despite the complete loss of expression of OAS1 or RNase L in the cells of P1 and P5, respectively (Fig. 2, E and F).