RAG2 and neoplasm: In transgenic zebrafish models of FN-RMS driven by rag2-kRASG12D, myf5-GFP+ tumor cells were shown to have a greater tumor-propagating potential when compared to more differentiated myosin light chain 2 (mylz2)-mCherry+ or intermediately differentiated myf5-GFP+/mylz2-mCherry+ cells (Ignatius et al., 2012).