Among the genes selectively altered in Eμ-xbp-1s B cells are those with known relevance to human MM pathogenesis, such as Cyclin D1, Cyclin D2, MAF, and MAFB (Figure 6A and data not shown) (Kuehl and Bergsagel, 2002; Shaffer et al., 2004). The gene discussed is MAF; the disease is Miyoshi myopathy.