Emerging evidence suggests that hypoxia encourages MM cell dedifferentiation and quiescence by reducing plasma cell-specific transcription factors (BLIMP-1, IRF4, XBP1), increasing B-cell gene expression signatures (PAX5, CD19, CD20 and CD45) and stem-cell markers (OCT4, NANOG, SOX2), as well as inducing reversible cell cycle arrest [192, 193]. The gene discussed is XBP1; the disease is Miyoshi myopathy.