SPHK1 and melanoma: Furthermore, we observed that melanoma patients treated with PD-1 blockade therapies with high SPHK1 (HR 0.30, 0.13–0.72), high MTA3 (HR 0.44, 0.20–0.95), high c-Myc (HR 0.16, 0.052–0.48) or high PD-L1 (HR 0.33, 0.14–0.80) expression levels in tumors exhibited prolonged progression-free survival (PFS; Fig. 6c-e and Supplementary Fig. 11f).