the similarity of the subject level to the reference level is not indicative of a predisposition to erfd for the tested subject as used herein a subject level is u201c similar u201d to a reference level if there is no statistically significant difference between the two levels in some embodiments a subject level differs significantly from the reference level of the same biomarker s when the reference level is from a reference subject who does not have a predisposition to erfd is indicative of a predisposition to erfd in the subject in some embodiments the biomarker for erfd can include one or more of e g tnf u03b1 stnfr1 stnfr2 fas and il 6 including any combination of tnf u03b1 stnfr1 stnfr2 fas and il 6 in some embodiments the biomarker for erfd can include tnf u03b1 stnfr1 stnfr2 fas and il 6 in some embodiments the biomarker for end stage renal disease esrd can include stnfr1 any method known in the art for determining levels of an analyte in a biological sample can be used an exemplary biochemical test for identifying levels of biomarkers employs a standardized test format such as the enzyme linked immunosorbent assay elisa see e g molecular immunology a textbook edited by atassi et al marcel dekker inc new york and basel 1984 for a description of elisa tests in some.