EIF2AK2 and breast neoplasm: Because increased NEU tumor growth in PKR−/− and eIF2αS/A mice could be mediated via cell-autonomous, as well as immune regulated mechanisms, we employed a mouse NEU breast tumor cell line, which was derived from MMTV-NEU NDL2-5 mice19, to impair PKR by the clustered regularly interspaced short palindromic repeats (CRISPR).