Nate Robinson defied the odds at 5 feet, 9 inches tall to win three NBA slam dunk contests, so he's no stranger to uphill battles. Sadly, he's dealing with another.

The former NBA vet announced he is undergoing treatment for kidney failure.

Perhaps even more stunning is Robinson has been battling it for four years.

"I'm sharing this now because I want to be the voice for all those who are having trouble speaking about this illness and come together for a greater cause — our health," he said in a statement.