The NSD2 (nuclear receptor binding SET [Suppressor of variegation 3–9, Enhancer of zeste, and Trithorax] domain protein 2) gene localizes on chromosome 4p16.3 and can produce two protein isoforms, namely full-length MMSET (multiple myeloma [MM] SET domain) and a truncated version, REIIBP (interleukin-5 response element II binding protein), via alternative transcription initiation events (1, 2, 3). The gene discussed is NSD2; the disease is AL amyloidosis.