LDLR and neoplasm: In human and mouse pancreatic ductal adenocarcinoma (PDAC), TAMs expressing high levels of Apo E can bind to low-density lipoprotein (LDL) receptors on the surface of tumor cells, which activates the NF-κB pathway and promotes the secretion of chemokines CXCL1 and CXCL5 (chemoattractants for immature myeloid cells) by cancer cells to inhibit CD8 + T-cell immune infiltration, ultimately promoting an immunosuppressive TME [66].