It is probable that calcifications are a predominant characteristic associated with the deposit of MSU in entheses, as shown by animal models of enthesitis, where local injection of monosodium urate crystals into the metatarsal entheses of oxidative-burst-deficient (Ncf1**) mice developed chronic enthesitis accompanied by massive enthesophytes by resonance magnetic imaging (35). Here, NCF1 is linked to enthesitis.