EIF2AK3 and Burkitt lymphoma: Interestingly, the 4 amino acid motif (DLLC) in the LMP1 transmembrane domain previously reported to interact with PERK [21] is retained in each of the LMP1 strains shown in S9 Fig, including B95.8, AG876, CAO, Akata (from a Japanese Burkitt lymphoma) and M81 (from a Chinese NPC), suggesting that the ability to inhibit PERK activity may be a shared feature of many different LMP1 strains.