For example, in 2007, the most studied zebrafish model of embryonic rhabdomyosarcoma (ERMS), a pediatric sarcoma exhibiting skeletal muscle features, was developed using a rag2 promoter to drive the expression of a constitutively active krasG12D gene in muscle satellite cells (Langenau et al., 2007). Here, RAG2 is linked to embryonal rhabdomyosarcoma.