Critical disease features in mice with myelodysplasia. Block plot showing clinical features (rows) present in the different mouse models (columns). The presence of dysplastic characteristics in the myeloid lineages identified to the left of the figure is indicated by blue squares. In addition to myelodysplasia, the mouse models in the right block show cytosis in one or more lineages (green squares), which in most cases is accompanied by cytopenia in a different lineage (black squares). The left block includes models that show only cytopenia (no cytosis). The red squares indicate the presence of a hypercellular marrow, increased cell death, or splenomegaly. Orange squares signify that leukemic transformation occurs in these animals. White squares indicate that the respective feature was absent or not reported for the model. The color(s) of the triangle indicate(s) the type of mouse model presented in the respective column: green indicates a conditional knockout model; orange a BM transplantation model with wild-type mice as recipients; blue, a knockout or knock-in model; yellow, a transgenic model. One of the 45 recipients transplanted with Dnmt3a^−/− HSCs developed chronic myelomonocytic leukemia, which is classified as an MDS/MPN overlap disease. Because it was only 1 mouse, this model was not included in the MDS/MPN category. *Peripheral blood cytopenia(s) in 1 of the 3 myeloid lineages is a requirement for the diagnosis of MDS. Leukopenia only signals that the total number of leukocytes is significantly lower than in control mice. However, it does not distinguish between lymphocytes, neutrophils, and monocytes. Information about the size of these subpopulations is essential to make the correct diagnosis. In addition, leukopenia that is only based on a lymphopenia does not fulfill the requirement for the diagnosis of MDS. ^†Numbers in the respective boxes represent the percentages that develop leukemia, whereas a “Y” denotes the fact that leukemia progression was reported but the proportion of animals was not clear.