Somatic ABCA1 mutations found in chronic myelomonocytic leukemia patients were found to impair cholesterol efflux and increase cell proliferation by enhancing the cholesterol-dependent IL3-receptor β pathway, which activates and protein-tyrosine kinase Janus kinase 2 (JAK2) and mitogen-activated protein kinase (MAPK) signaling [309] (Figure 3). This evidence concerns the gene JAK2 and chronic myelomonocytic leukemia.