HLA-G and melanoma: On the other hand, HLA-G has been found to be secreted associated to extracellular vesicles; i.e., exosomes originated by the endo-lysosomal pathway, derived from melanoma cells (25) and placental trophoblasts (26), which provide another mechanism for tumors to modulate the host immune response and for trophoblasts to modify the maternal immunological environment.