In contrast, when the frequency of Treg cells was analyzed on the basis of CD39 expression, it was significantly and positively correlated with the collective serum HBV viral copies in all tested hepatitis B patients (n = 53, r = 0.344, P = 0.012); however, in concrete disease status, significant correlation was only observed in AsCs patients (r = 0.685, P = 0.022) (Figure 4A, middle panel). The gene discussed is ENTPD1; the disease is hepatitis B virus infection.