HOXD9 and hepatocellular carcinoma: Chen et al. established an independent prognostic signature (including gene KPNA2, CDC20, SPP1, and TOP2A) for patients with HCC, and Long et al. developed a four-gene-based model (HOXD9, MAGEB6, SPP1, and CENPA) that accurately predicted prognosis 45, 59.