RAG1 and neoplasm: The growth of PDV tumors in immunodeficient Rag1 knockout (KO) mice (B6.129S7-Rag1tm1Mom/J) in contrast to the immunocompetent B6 mice demonstrates that PDV tumors are immunologically rejected in B6 mice; furthermore, PDVC57 tumors may modulate the immune microenvironment to promote tumor growth27.