Based on the critical role of BAG3 in the stimulation of the autophagy pathway, it is tempting to suggest that bortezomibinduced phosphorylation of BAG3 might play an important role in autophagy activation. Therefore, the increase in BAG3 phosphor-ylation is likely part of the cell's response to bortezomib treatment and appears to represent a novel mechanism with a link between the two protein degradation systems. This speculative idea, however, is not yet supported by the current experimental data, and further investigations are undergoing to determine the functional implication of BAG3 in coordination between the proteasome and autophagy.