BTLA and Ascites: We found that the MFI of BTLA expression on CD4+ T cells increased in co-infected patients compared with that in non-infected patients (Fig. 1g), while no significant differences were noted in patients with HBV-ACLF with or without ascites complications, as well as in Hepatitis B virus e antigen (HBeAg)-positive or HBeAg-negative patients (Supplementary Figs. 1d, 4b).