S100B and melanoma: Along with first-line treatment, S100B plasma levels and metastatic stage at advanced melanoma diagnosis were independently selected in the multivariable model, which showed that patients treated with ICI in the first line had a reduced risk of MBM development compared with patients who received targeted therapy (HR 2.86, 95% CI 1.53–5.37, p = 0.001), chemotherapy (HR 3.37, 95% CI 1.63–7.00, p = 0.001), local therapy (HR 3.16, 95% CI 1.64–6.09, p < 0.001), and no treatment (HR 11.24, 95% CI 5.14–24.59, p < 0.001).