EIF2AK2 and infection: 1) HPIV3-induced SG formation is PKR dependent, but AS-induced SG formation is not (Fig 4A and 4B; S3C and S3D Fig); 2) HPIV3-induced SGs are rich of viral mRNAs, while AS-induced SGs are not (Fig 5A); 3) HPIV3-induced SGs go through a longer period of time during infection (24 h) than AS treatment (1.5 h) (Fig 2A–2D).