Due to a homozygous Rag1 gene deletion, this model lacks mature T and B lymphocytes (Mombaerts et al., 1992); therefore, it can be used for human tumor xenograft and cancer cell implant studies (O'Neill et al., 2016; Ray et al., 2007; Zaytouni et al., 2017). This evidence concerns the gene RAG1 and neoplasm.