Based on these results, the correlation between the expression of HOXD1, HOXD3, and HOXD4 and the cancer pathogenesis, underlying mechanisms, and tumor immunity were studied in this research, which was the first comprehensive analysis of the differential expression and related mechanisms of HOXD1, HOXD3, HOXD4 in various cancers. The gene discussed is HOXD4; the disease is neoplasm.