SS is thought to arise from expansions of mature long-lived CD4+CD7- T-cells with a CD45RO+CD27+CD62L+ TCM phenotype accompanied by a consistently high CCR7 mRNA and protein expression, whereas CCR7 expression in the predominantly TEM cells from cutaneous MF lesions is controversial (165, 178–182). The gene discussed is CD4; the disease is mycosis fungoides.