Andreev found that eosinophils can inhibit osteoclast‐mediated bone resorption via eosinophil peroxidase (EPX) secretion, helping to maintain bone homeostasis and relieve rheumatoid arthritis (RA).[28] While EPX regulates bone homeostasis,[28] the role of eosinophils and their granule protein eosinophil major basic protein (EMBP),[29, 30, 31] in cartilage and bone remodeling remains unexplored. Here, PRG2 is linked to rheumatoid arthritis.