Just who is this Gamboa dude 50 Cent keeps referencing in his Twitter beef with Floyd Mayweather? Well, Yuriorkis Gamboa is an undefeated (21-0, 16 knockouts) Cuban boxer, a former WBA and IBF featherweight champion, and the flyweight gold medalist from the 2004 Athens Olympics. He's signed on to 50 Cent's SMS Promotions and, according to Fif, has a shot at beating the 43-0 Floyd Mayweather. 50 Cent went to Twitter to further stress the point: 

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