TFRC and endometriosis: Initial univariate analysis determined different levels of suPar (Mann–Whitney test; p = 0.024) and IL-6 (Mann–Whitney test; p < 0.001) between the endometriosis group and our control group; levels of hepcidin, CRP, sTfR and ferritin did not vary significantly between groups, refer to Table 2 for an optical display.