TIFAB and myelodysplastic syndrome: Another gene constantly deleted in del(5q) MDSs is the TRAF-interacting protein with forkhead-associated domain B (TIFAB); TIFAB gene haplo-insufficiency may contribute to the MDS phenotype through two different mechanisms: TIFAB acts as a repressor of TRAF6 since it forms an unstable complex with this protein, reducing TRAF6 protein stability; TIFAB-deficient mice display a number of defects of hematopoiesis, including an altered number of HSCs/HPCs, impaired myeloid differentiation and progressive cytopenia [116].