Figure 2: Immunofluorescence analyses in the skin of the patient (×400). FoxP3 is a master regulatory gene for function of Tregs. a-1, b-1) Both FoxP3- positive and CCR4-positive lymphocytes were substantially decreased when psoriasis vulgaris emerged, 13 lymphocytes per 10 HPF and 12 lymphocytes per 10 HPF, respectively. a-2, b-2) In contrast, after psoriasis vulgaris improvement, both FoxP3-positive and CCR4-positive lymphocytes without atypical nuclei were markedly increased 39 lymphocytes per 7 HPF and 26 lymphocytes per 7 HPF, respectively. c-1) Graphic demonstration of the cell counts per one HPF as results of immunofluorescence analyses. When the skin lesions of psoriasis vulgaris were improved, FoxP3-positive lymphocytes without atypical nuclei were increased approximately 4 times and CCR4- positive lymphocytes without atypical nuclei also increased approximately 3 times, respectively. Consequently, normal Tregs showed a marked trend to decrease. c-2) Graphic demonstration of the cell counts per one HPF as evidenced by immunofluorescence analyses. FoxP3-positive lymphocytes with atypical nuclei were substantially reduced approximately a quarter and CCR4-positive lymphocytes with atypical nuclei, which corresponded to residual ATL cells, were also substantially reduced approximately ninth. d-1, d-2) CD4-positive lymphocytes also decreased. These findings indicate that her skin erythemas were caused by dysfunction of normal Tregs, rather than skin invasion of residual ATL cells.