MYD88 and infection: Several main players of innate immunity, such as signal transducer and activator of transcription 1 (STAT1), myeloid differentiation primary response gene 88 (MyD88), TLR4, TLR7 and TLR3/TIR-domain-containing adapter-inducing interferon-β (TRIF), function to dampen infection severity during coronavirus infection in vivo [13,14,15,16,17].