SPP1 and melanoma: In the present investigation, plasma levels of interleukin-8 (IL-8), C–C motif chemokine ligand 4 (CCL4), osteopontin, leukemia inhibitory factor (LIF) and brain derived neurotrophic factor (BDNF), were determined at baseline, after 2 months of treatment and, when feasible, at progression, in a cohort of 70 stage III-IV melanoma patients subjected to BRAFi monotherapy or the combination of BRAFi and MEKi and their association with clinical response, PFS and OS was evaluated.