FGF21 and myelodysplastic syndrome: In this regard, the most efficient discrimination points were as follows (cut-off values for pGSN, FGF-21, and GDF-15 are displayed in Table 3): pGSN concentrations under 252 μg/mL diagnosed MDs with 66.10% sensitivity and 98.21% specificity; for FGF-21, a threshold value of 300 pg/mL diagnosed MDs with 61.67% sensitivity and 83.93% specificity, and for GDF-15, a threshold value of 975 pg/mL diagnosed MDs with 71.93% sensitivity and 92.86% specificity.