Protein kinase R and its cellular regulators in cancer: An active player or a surveillant?

Protein kinase R (PKR), originally known as an antiviral protein, senses various stresses as well as pathogen‐driven double‐stranded RNAs. Thereby activated PKR provokes diverse downstream events, including eIF2α phosphorylation and nuclear factor kappa‐light‐chain‐enhancer of activated B cells activation. Consequently, PKR induces apoptosis and inflammation, both of which are highly important in cancer as much as its original antiviral role....