Immunohistochemical staining of ATF5 (Figure 1B) and immunofluorescent co-staining with CD3 (Figure 1C) on lesional biopsies confirmed the increased expression of ATF5 protein in atypical CD3+ T cells from CTCL patients compared to normal CD3+ T cells from benign inflammatory dermatoses patients. The gene discussed is ATF5; the disease is primary cutaneous T-cell non-Hodgkin lymphoma.