By employing a co-culture system of HepLPCs and HCC cells, we found that HepLPCs markedly inhibited HCC growth by prompting mitochondrial dysfunction, which further led to the co-inhibition of the Notch1 and JAK1/STAT3 signaling pathways through paracrine actions involving S-adenosylmethionine (SAM) and Nicotinic acid (NA). The gene discussed is JAK1; the disease is hepatocellular carcinoma.