As shown in Figure 4A–4B, the comparison of the relative protein concentration of characteristic gene expression showed that the protein concentrations of CCKBR, ITGA10 and IGFBP1 in melanoma tumor tissue in the postoperative chemotherapy group were significantly higher than those in the immunotherapy group while the protein concentrations of KCNJ11, NMU, MMP13 and CEACAM5 in the chemotherapy group were significantly lower than those in the immunotherapy group. Here, CEACAM5 is linked to melanoma.