In SLE patients, a negative correlation was found between serum sTfR levels and HGB levels (p = 0.0001), HCT (p = 0.008), MCV (p = 0.0001), MCH (p < 0.00001), and MCHC indexes (p < 0.00001), and the lymphocyte count (p = 0.0005). This evidence concerns the gene PMCH and systemic lupus erythematosus.