HMMR-AS1 is upregulated in HCC, correlating with poor prognosis; its inhibition suppresses tumor growth. It promotes M2 macrophage polarization and HCC progression by competitively binding miR-147a to stabilize ARID3A. HIF-1α enhances HMMR-AS1 transcription and exosome secretion under hypoxia. The gene discussed is HMMR; the disease is hepatocellular carcinoma.