CD4 and primary cutaneous T-cell non-Hodgkin lymphoma: Notably, in CTCL, the cell surface expression of receptors, such as CD7 and CD26, tends to become downregulated on the surfaces of malignant T cells In this study, we analyzed single-cell RNA sequencing (scRNA-seq) data from patients at two institutions with mycosis fungoides (MF), the most common subtype of CTCL with a predominantly CD4 phenotype.