TNFSF13B and infection: BAFF levels were increased in the sera of patients with HCV-associated MC (n = 45, 1,389.0 ± 92.2 pg/ml) compared to those who had HCV infection but no MC (n = 20, 1,061.8 ± 61.6 pg/ml, P < 0.05), those without infection (n = 25, 632.2 ± 53.9 pg/ml, P < 0.005), or HC subjects (n = 20, 300.0 ± 14.8 pg/ml, P < 0.005).