Figure 1.

Signaling pathways involved in the regulation of apoptosis and proliferation of marrow cells in patients with MDS. In early stage disease pro-apoptotic signals predominate (1A). The interplay of pro-apoptotic, TNF/Fas/TRAIL, and anti-apoptotic signals, represented here by NF-κB and PI3K/AKT, is central to disease progression (1B).

TNF-α = tumor necrosis factor α; TRAIL = TNF-related apoptosis inducing ligand; R1/R2 = Receptor 1/Receptor 2. (For additional abbreviations, see text.)