Postnov et al. (2009) generated two human MM cells, U266 and RPMI-8226/S, with the luciferase-GFP genes and engrafted these cells into total-body irradiated RAG2–/–γc–/– mice at 24 h before transplantation. It showed that MM cells spread across the skeleton and severe bone lesions (Postnov et al., 2009). The gene discussed is RAG2; the disease is Miyoshi myopathy.