C3 and metabolic dysfunction-associated steatohepatitis: PIIINP levels alone represent a good diagnostic biomarker for fibrosis [56], but it has been demonstrated that Pro-C3 (the PIIINP neo-epitope) reflects the effective production of collagen III biosynthesis [57]; furthermore, the increase of serum Pro-C3 levels is correlated with NASH and fibrosis [58].