GSK3B and myelodysplastic syndrome: Using mice that were deficient for the negative regulatory kinase GSK3β (and also its homolog GSK3α), Bhatia and coworkers showed that these mice have high Wnt signaling in their HSCs and develop a myeloplastic syndrome (MDS) similar to human MDS [33] which is seen as a precursor stage to full blown AML [34].