CD4 and mycosis fungoides: After this, several studies have confirmed that TOX is aberrantly expressed in CD4+ /CD8− neoplastic T cells in MF and SS [2, 6, 7, 15, 19, 20, 29], so as to be aberrantly expressed in CTCL with CD4−/CD8+ and CD4−/CD8− phenotypes [24], differentiating malignant from non-malignant skin-infiltrating T cells found in benign inflammatory dermatoses [31].