Considering that p-eIF2α levels are upregulated in response to various stresses, including viral infection, radiation, and ER stress, and that PERK is only one of the four eIF2α protein kinases, salubrinal does not necessarily reflect the role of the UPR signaling pathway PERK-eIF2α in osteoclastogenesis [25,120]. This evidence concerns the gene EIF2A and viral infectious disease.