SPHK1 and melanoma: Furthermore, we delineated the expression of SPHK1, MTA3, c-Myc, and PD-L1 and tumor-infiltrating immune cell profiles in melanoma biopsies from a total of nineteen patients regularly receiving PD-1 blockade therapies (toripalimab; Fig. 6a, b and Supplementary Fig. 11d, e).