Fn14 expression in the normal adult mouse pancreas was difficult to detect by immunostaining (data not shown) but was highly expressed by normal pancreatic duct cells at mRNA level (n = 3; values normalized to GAPDH were 0.014, 0.016, and 0.013, values comparable to positive control mouse lupus kidney samples); it is possible that Fn14 expression was upregulated during the isolation process. This evidence concerns the gene GAPDH and systemic lupus erythematosus.