IL6 and Fabry disease: In addition, FD is associated with proinflammatory status, as demonstrated in the plasma of FD patients by increased expression of the proinflammatory cytokines IL-1β and TNF-α, compared to normal controls [37] as well as levels of IL-6 and TNF-α [14], both cytokines being negatively correlated with bilirubin concentrations as shown in both experimental and clinical studies [38, 39].