Our observation that IL-1R−/− mice are protected from perivascular fibrosis in the liver and muscle during chronic Toxoplasma cachexia are consistent with these data and previous studies showing that pharmacological or genetic blockade of IL-1R signaling in mice attenuates fibrosis in the liver38,84,85, heart86,87, and lungs87,88. This evidence concerns the gene IL1R1 and Cachexia.