A recent study using a multi-omic systems immunology approach toward the profiling of CTCL patients from two anti-PD-1 clinical trials identified CD39, together with CD95 and KIR3DL2, as the most discriminatory markers for neoplastic T cells in leukemic CTCL patients [50]. This evidence concerns the gene FAS and primary cutaneous T-cell non-Hodgkin lymphoma.