To examine whether T-cell differentiation stage fluctuated depending on the patient’s clinical response to immunotherapy, the frequencies of differentiation stages (N: naive; CM: central memory; EM: effector memory; EMRA: effector memory re-expressing CD45RA) of γδ2+T, γδ2–T, CD8+ T and CD4+ T cells were evaluated in melanoma patients undergoing anti-PD1 treatment using flow cytometry. This evidence concerns the gene CD4 and melanoma.