For example, infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pathogen that causes the current coronavirus disease 2019 (COVID-19) pandemic, is recognized by various PRRs, most prominently the RLR melanoma differentiation-associated protein 5 (MDA5) and TLRs, such as TLR2 [2], 3 [3] and 4 [4]. The gene discussed is IFIH1; the disease is infection.