TLR3 and susceptibility to pneumonia measurement: The deficiencies of autosomal Toll-like receptor 3 (TLR3) and TLR7 linked to the X chromosome are inborn errors of type I interferons that are found in around 1% to 5% of younger patients (under 60 years old) with critical pneumonia, while a lower proportion of older patients have them (Zhang et al. 2022a).