NR4A1 and neoplasm: First, this study included a heterogeneous population with respect to factors such as tumor biology (i.e., status of hormonal receptors and human epidermal growth factor receptor), tumor burdens in intrahepatic and extrahepatic disease, responses to systemic treatments, and various histories of pre- and post-treatments; thus, potential selection bias and confounding factors related to prognosis were not thoroughly evaluated.