Zhu and colleagues treated immunocompetent glioma-bearing mice with a Dakar strain of ZIKV which was serially passaged through a Rag1-/- mouse, thereby increasing its virulence, specifically in mice [21], while Chen and colleagues treated immunodeficient tumor-bearing mice with a live-attenuated Cambodian strain [22]. The gene discussed is RAG1; the disease is glioma.