In patients with melanoma, the relative median percentages were 22.40 [16.95; 37.15] for CD4+CD26neg (Fig. 1A), 69.50 [58.70; 75.55] for CD4+CD26int (Fig. 1B), and 7.30 [4.70; 10.90] for CD4+CD26high (Fig. 1C). Here, CD4 is linked to melanoma.