These data, along with the results on Stat3/14-3-3ζ interaction, support the model that multiple signaling events, including PKC, Raf1, MEK1/2, ERK1/2 and PP2A, impinge on Stat3 and that 14-3-3 proteins serve as an essential coordinator for different pathways to regulate Stat3 activity in myeloma cells (Fig. 6). This evidence concerns the gene PTPA and plasma cell myeloma.