Antonio DeMarco was speaking about his pursuit of a world junior-welterweight title Wednesday, and it was as if the details of fight preparation turned trivial.
"Mostly today, I fight for the life of my sister -- it's for her that I'm going up in the ring that night," DeMarco said in Spanish to a translator.
The Tijuana fighter usually resides near trainer Freddie Roach's Wild Card Boxing Club in Hollywood during training. He was distraught upon arriving last month to work with Roach in the Philippines.
A phone call from home in Mexico left DeMarco stunned to learn that doctors had detected bone cancer in the shoulder of his 13-year-old sister, Mariana.
She's begun receiving chemotherapy treatments.
"Right now, the doctors give her a good probability of [survival], but it's hard process," DeMarco said. "She's braver than me."
DeMarco (31-3-1, 23 knockouts), who'll fight Las Vegas' Jessie Vargas (25-0) for Vargas' World Boxing Assn. junior-welterweight belt Saturday night on HBO pay-per-view at the Venetian Macao's Cotai Arena, has dedicated his career to his family.
"Believe me, winning that world title would be a great motivation to her," DeMarco said. "She would see everything in life can be accomplished. All you need is a dream and to work hard. I'm fighting for her dream to have a life."
The oldest of three children, DeMarco as a teenager left home to fight in Tijuana, scavenging for his own meals wherever possible – "cold nights, hungry days," he said -- while sending purse money home.
He ultimately twice won lightweight world titles, only to lose the belts to the late Edwin Valero and Adrien Broner.
Now 28, he's won three consecutive fights in Baja, Mexico, to gain this title shot.
Mariana DeMarco is being treated at a cancer hospital in Tijuana, DeMarco said.