BDNF and plasma cell myeloma: Thalidomide is a glutamic acid derivative for the treatment of multiple myeloma [117], thanks to its immunomodulatory activity, which blocks both the production of tumor necrosis factor-alpha (TNF-α) and the activation of NF-kB (nuclear factor kappaB), resulting in the dysregulation of neurotrophins with their receptors which accelerates neuronal cell death [180].