The use of a transgenic mouse model for cancer xenotransplantation has confirmed that a lack of SIRT4 can accelerate the progression of cancer cell death in various cancers by regulating glutamine metabolism in the mitochondria or the mammalian target of rapamycin (mTOR) pathways (Csibi et al., 2013; Jeong et al., 2013). Here, MTOR is linked to cancer.