Biological effects exerted by PEDF in chondrocytes. GSEA shows significantly enriched biological processes and signaling pathways based on the gene sets positively and negatively correlated with PEDF treatment (a). PEDF-treated or nontreated three-dimensional cell pellets were analyzed by Toluidine blue (TB) staining and MMP13 immunohistochemistry (b). RNA-Seq data were confirmed by qRT-PCR showing the n-fold expression of significantly positively and negatively regulated genes with relevance for the skeletal system (c). Bars show the mean and SD. Bar = 1 mm.