PPP1R15A and viral infectious disease: Growth arrest and DNA damage inducible protein 34 (GADD34) was originally isolated based on ultraviolet-inducible transcripts in Chinese hamster ovary cells.18 The expression of GADD34 is induced by several cellular stresses, such as DNA damage, endoplasmic reticulum (ER) stress, and amino-acid deprivation.19, 20, 21, 22 Recently, it was reported that GADD34 is linked to cytokine production in response to viral infection.