XDH and gout: The Gout, Hyperuricemia and Crystal-Associated Disease Network (G-CAN) has published recommendation to differentiate gout states clarifying terms such as for example, urate (circulating form of the molecule generated by xanthine oxidase), gout flare (acute inflammation facilitated by MSU crystals), or tophus (congregation of MSU crystals and host response tissue forming a delineated structure in soft tissues) [5].