In cutaneous T-cell lymphoma (CTCL) subtypes including Sézary Syndrome (SS), Mycosis Fungoides (MF), and Cutaneous T-Cell Lymphoma Not Otherwise Specified (CTCL-NOS), CCR10 is expressed by tumor-infiltrating lymphocytes (TILs) and malignant clones, with ~10-fold higher transcripts levels during leukemic phases and frequent chromosomal alterations involving isochromosome 17 (92, 93). The gene discussed is CCR10; the disease is mycosis fungoides.