GJIC is also involved in antigen presentation through direct coupling between monocytes and DCs [222], between DCs [223], between tumor cells and endothelial cells [224], and at the immune synapses formed between melanoma cells and CD4+ T cells [225], melanoma cells and natural killer (NK) cells [226], and DCs and CD4+ T cells [227]. The gene discussed is CD4; the disease is melanoma.