Moreover, whereas inhibition of GRP94 through PU-WS13 has been shown to reduce the stability of HER2 in a tumor-specific manner where siGRP94 mimics the effect of PU-WS13 to destabilize HER224, in this study we found that whereas PU-WS13 rescues the folding, secretion, and function of AAT-Z, silencing through siGRP94 does not rescue AAT-Z defects. This evidence concerns the gene HSP90B1 and neoplasm.