The group of downregulated proteins in DD tissues included several proteins with known antifibrotic properties, such as cartilage oligomeric matrix protein (COMP), proteoglycan 4 (PRG4), growth differentiation factor 10 (GDF10), bone morphogenetic protein 3 (BMP3), and annexin A1 (ANXA1) (Figure 1C). Here, PRG4 is linked to dentin dysplasia.