The active site lies between the identical subunits and has the characteristic Asp-Thr-Gly (Asp25, Thr26 and Gly27) sequence common to aspartic proteases.
Je eden petih tenisačev, ki so osvojili turnirje za Grand Slam na travi, pesku in trdi podlagi, ob njem še Jimmy Connors, Andre Agassi, Rafael Nadal in Roger Federer.