EGR1 and Miyoshi myopathy: Based on the findings that EGR1/Egr1 was markedly upregulated in both serum and cartilage tissues (RNA/protein levels) in the KOA, AS and MM groups in advanced disease models, whereas in the serum of clinically mildly ill patients, Egr1 was elevated only in the AS group, its reliability may be suggested as a KOA-AS multimorbid hub gene with transformation into a generalized marker in advanced stages.