EIF2A and infection: Phosphorylation of downstream target eIF2α occurred only during NL63 infection in A549ACE cells, whereas p-eIF2α levels were not increased above mock during NL63 infection of MRC-5 cells or during 229E infection of either cell line (Fig. 5A and B), suggesting incomplete activation of the PKR pathway or phosphorylation of eIF2α that is below the level of detection via western blot.