In this study, 17-AAG (Figure S3), an HSP90 inhibitor candidate in human clinical trials (multiple myeloma; phase 3), potentially exerted an inhibitory activity on EZH2, PAX5 and KHDRBS1 genes associated with the risk of developing metastatic phenotypes (Figure 8) by modulating gene expression (Figure S7). This evidence concerns the gene KHDRBS1 and AL amyloidosis.