Whereas two old studies highlighted its ability to decrease myeloma cell growth through the down-regulation of NFκB activity [29,30], two very recent papers demonstrated PPAR β/δ upregulation in the BM CD138+ plasma cells and BM CD138− microenvironment cells in patients with newly diagnosed MM compared with those in normal BM controls, and a higher PPAR β/δ expression was associated with worse progression-free survival (PFS) and overall survival (OS) [31,32]. This evidence concerns the gene SDC1 and plasma cell myeloma.