HPDL showed a negative correlation with the infiltration of cancer-associated fibroblasts (CAFs), lymphoid progenitors, myeloid progenitors, endothelial cells (Endo cells), hematopoietic stem cells (HSCs), macrophages, mast cells, CD8+ T cells, CD4+ T cells, natural killer T cells (NKT cells), and gamma/delta T cells (g/dT cells) in the majority of tumors. The gene discussed is CD4; the disease is cancer.