Fig 1: Pre- (left side) and post-treatment (right side) bone marrow biopsies of a male patient suffering from acute myeloid leukemia with myelodysplasia-related changes, who has been treated with chemotherapy and additional lenalidomide. a Conventional morphology at initial diagnosis, H&E. b Conventional morphology before the second induction cycle, H&E. c CD34 staining revealing higher microvessel density and partial positivity of the leukemic blasts and the dysplastic megakaryocytes before treatment, immunoperoxidase. d CD34 staining of the post-treatment biopsy before the second induction cycle illustrating a significant decrease of the microvessels and complete absence of positively staining blasts and megakaryocytes, immunoperoxidase. e, f Increasing amount of CD8-positive T cells from 2% pre-treatment (e) to 15% post-treatment (f), immunoperoxidase. g, h Increasing amount of T-bet-positive T-helper cells from 1% pre-treatment (g) to 9% post-treatment (h), immunoperoxidase