DMF treatment induces massive cell death specifically within CTCL tumors in vivo. HH xenografted tumors grown intradermally in NSG mice that were treated once daily IP with either 30 mg/kg bodyweight DMF or PBS. (A) Representative hematoxylin and eosin–stained specimens of primary HH tumors (upper panels, 20×; lower panels, 200×). (B) Representative pictures of immunofluorescent stainings of primary HH tumors stained for cleaved caspase 3, CD3, and with Hoechst dye, the latter to counterstain nuclei. (C) Semiquantitative score of necrosis areas in the primary xenograft tumors (0% to 25% tumor area covered by necrosis = 0; 25% to 50% tumor area covered by necrosis = 1; 50% to 75% tumor area covered by necrosis = 2; 75% to 100% tumor area covered by necrosis = 3). (D) Quantification of cleaved caspase 3 (left) and cleaved caspase 8 (right) mean fluorescence intensity in HH tumors of either the PBS or DMF treatment group (n = 3 each). (E) Representative immunofluorescent pictures of primary HH xenograft tumors of a PBS- and a DMF-treated mouse stained for cl Casp3, p65, and with Hoechst dye. *P < .05.