GDF2 and metabolic dysfunction-associated steatohepatitis: The current study also showed serum BMP9 levels differentiated NASH at-risk (58.13 ± 2.82 ng/L) from the other groups: healthy control (70.32 ± 3.70) and NAFL (64.34 ± 4.76 ng/L, p < 0.0001).