TLR9 and melanoma: The presence of plasmocytoid dendric cells (pDCs) expressing TLR7 and TLR9 receptors in the inflammatory infiltrate of melanoma metastasis is crucial for treatment with two potent immune stimulators after ECT, such as imiquinod, a TLR7 agonist, and GpG-ODN, a TLR9 agonist.