CD4 and melanoma: To explore the function of circulating effector cells in melanoma patients following anti-PD1 treatment, cytokine production by γδ2+T, γδ2–T, iNKT, CD8+ T, CD4+ T, NKbright and NKdim cells was assessed by intracellular cytokine staining after PBMC stimulation by PMA/Iono using flow cytometry (Supplementary Figure 9A).