AR IFNAR1 deficiency has recently been detected in previously healthy unrelated adults with hypoxemic COVID-19 pneumonia (Zhang et al., 2020), and AR IFNAR1 deficiency has been reported in four children with hypoxemic COVID-19 pneumonia (Khanmohammadi et al., 2022; Zhang et al., 2022b; Abolhassani et al., 2022). Here, IFNAR1 is linked to hyperinsulinemic hypoglycemia, familial, 4.