Overexpression of CD44 has been observed in lenalidomide-resistant human multiple myeloma cell lines (HMCLs), with increased adhesion to bone marrow (BM) stromal cells, while inhibition of CD44 reduced the adhesion of multiple myeloma cells and reversed the resistance to lenalidomide (Spaan et al., 2018). This evidence concerns the gene CD44 and AL amyloidosis.