In addition to the immune system parameters described above (immune indices and cytokine release), knowledge of serum levels of melanoma tumor markers, such as serum lactate dehydrogenase (LDH) and S100, could provide useful information regarding the metabolic activity of tumor cells and tumor progression (tumor growth and tumor burden) by their individual or corroborated assessment during immunotherapy [37,38,39,40,41,42,43]. The gene discussed is S100B; the disease is melanoma.