Cao et al. [81] showed that MMP8 secreted by irradiated liver nonparenchymal cells enhanced the migration and invasion of HCC through modulation of AMP-activated protein kinase (AMPK)/mammalian target of rapamycin signaling, providing a possible mechanism in sublethal irradiation-induced HCC metastasis observed often in radiotherapy. This evidence concerns the gene MTOR and hepatocellular carcinoma.