When the two viruses were compared, the lethal PdR-H30K-5U virus dominated in downregulating pathways associated with the immune system, such as the Th17 cell differentiation pathway, Th1 and Th2 cell differentiation pathway, human T-cell leukemia virus 1 infection pathway and Epstein-Barr virus infection pathway (Figure 7c and Figure S1). The gene discussed is POLA1; the disease is Epstein-Barr virus infection.