Multiple myeloma is a malignant cancer of plasma cells that remains to date incurable. One factor that contributes to multiple myeloma drug resistance is the interaction between myeloma cells and the components of their microenvironment. This interaction causes a change in cell growth characteristics of myeloma cells so that they somehow become less susceptible to drug toxicity. The objective of this proposal is to assess how a cell adhesion protein, fibronectin, regulates this resistance to drug toxicity.