In MDS, the immune response is altered; previous studies have shown polyclonal/oligoclonal expansion of CD4+ and CD8+ T cells in both blood and bone marrow [28, 29], changes in the numbers of Treg [30–32], an increase in IL-17A-producing T cells [31], and immune-mediated autologous cytotoxicity against hematopoietic precursor cells [33]. The gene discussed is IL17A; the disease is myelodysplastic syndrome.