They analyzed skin biopsies from 42 prelymphomatous T cell dyscrasias (CLD), 9 Sezary’s syndrome (SS), 103 MF, and 20 CD30+ lymphoproliferative diseases (LPD) for programmed death marker-1 (PD-1) expression using immunohistochemistry. This evidence concerns the gene TNFRSF8 and congenital secretory chloride diarrhea 1.