HLA-DPB1 and neoplasm: Moreover, the communication between tumor and immune cells was more widespread in the HER2neg group, especially in immune response-related crosstalk between tumor cells and myeloid cells (which was primarily comprised of macrophages; Additional file 7: Fig. S7B), such as “HLA-DPB1–TNFSF13B” and “TNFRSF1A–GRN” (Additional file 7: Fig. S7C).