TLR7 and systemic lupus erythematosus: Loss-of-function mutations in TLR7 are a genetic risk factor for the development of COVID-19 pneumonia (Brown et al., 2022), whereas gain-of-function mutations in TLR7 and TLR8 drive immune disorders such as systemic lupus erythematosus (Aluri et al., 2021; Brown et al., 2022).