We fitted multivariate models with all variables, EBV infection and lower frequency of CD4+/PD-1 were revealed as independent factors (OR 41.7, 95%CI 5.2–337.2, p < 0.0001 and OR 0.9, 95%CI 0.8–0.9, p < 0.0001). The gene discussed is PDCD1; the disease is Epstein-Barr virus infection.