SOCHI, RUSSIA -- The 2014 Winter Paralympic Games in Sochi began Friday.
The U.S. is sending 80 athletes and the team is billed as the largest of any nation in Sochi, with 58 men and 22 women, and up from 50 athletes in 2010.
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Here are five storylines to watch:
1. Tatyana McFadden eyes history in homecoming
The most decorated U.S. Paralympian in Sochi will be an athlete making her Winter Games debut. McFadden, 24, is a 10-time Paralympic medalist from the 2004, 2008 and 2012 Summer Games.
She's coming off an unprecedented 2013, when she became the first woman to win six gold medals at a single International Paralympic Committee Track and Field World Championship. She also captured the first major marathon "Grand Slam," sweeping Boston, London, Chicago and New York City last year.
McFadden is less decorated on snow. She picked up cross-country skiing less than two years ago and has five top-10s but no podium finishes in World Cups.
Sochi marks a bit of a homecoming for McFadden, who was born in Russia paralyzed from the waist down due to spina bifida and adopted from a St. Petersburg orphanage at age 6. She was encouraged to pick up cross-country skiing by Alana Nichols, the first woman to win gold medals in the Summer (wheelchair basketball) and Winter (Alpine skiing) Paralympics.
McFadden would love to match Nichols' accomplishment in Sochi, but said she's still learning how to deal with different snow conditions. There are four cross-country events - the 1km sprint, 5km, 10km and 15km.
"The sprint is my favorite," McFadden said. "I love the sprint in track, and I love the sprint on skis. The hardest distance is definitely the longer distance because it takes a lot more technique."
Another U.S. cross-country skier, Oksana Masters, was born in Ukraine. She won a 2012 Paralympic bronze medal in rowing and may be a better cross-country medal threat than McFadden.
She was born with deformities that caused her to have both legs amputated as a child, having been exposed to radiation from the Chernobyl nuclear power plant disaster in 1986. Like McFadden, she was adopted from an orphanage as a young girl. Masters has also posed in the ESPN the Magazine Body Issue.
2. U.S. ice sledge hockey team defends 2010 gold
The U.S. went undefeated in the sledge hockey tournament in Vancouver in 2010, not allowing a goal en route to gold. It could be in for a tougher fight this time after taking silver behind Canada at the 2013 World Championships.
Goalie Steve Cash leads the returning players from the 2010 team. Cash stopped all 33 shots over five games four years ago. He lives and trains in St. Louis with teammate Josh Pauls, one of the most improved forwards over the last few years. Pauls was the youngest member of the 2010 team at age 17.
First-time Paralympians forwards Josh Sweeney and Rico Roman are retired military athletes with Purple Hearts who both lost limbs via improvised explosive devices (IEDs).
A retired Marine Corps Sergeant, Sweeney, 26, became a bilateral amputee after stepping on an IED in Afghanistan in 2009. Roman, 33, is a retired Army Staff Sergeant who had his left leg amputated above the knee after being wounded by an IED in Iraq in 2007.
3. Snowboarding's Paralympic debut
The U.S. could benefit greatly from the addition of a snowboarding event in Sochi, just as it did in the Olympics. Americans are medal threats in men's and women's snowboard cross.
Amy Purdy and Heidi Jo Duce lead the charge on the women's side. They're tied for No. 2 in the world rankings.
Purdy, 34, survived bacterial meningitis in 1999 but lost both her legs and later needed a kidney from her father at age 20. She built her own snowboard and is seen as instrumental in getting snowboarding into the Paralympic program. A model, she's been in a Madonna music video and on "The Amazing Race" in 2012. She's going on "Dancing with the Stars" this season, beginning one day after the Closing Ceremony.
Duce, 23, has only been snowboarding competitively for 14 months. She entered her first snowboard cross event in early 2013 and was the national champion by the end of the year.
The U.S. men could sweep the podium with the world's top two riders, Evan Strong and Mike Shea,and Keith Gabel.
4. Wife hopes husband can help her to gold
Danelle Umstead competes in visually impaired Alpine skiing with her husband, Rob, as her guide. Together, they won super combined bronze in 2010. She could fare even better in Sochi given she finished No. 1 in the 2013-14 World Cup standings.
Umstead, 42, met her husband while skiing in New Mexico. Rob has been her guide since 2008. She has the eye disease retinitis pigmentosa, has no central vision and is losing her peripheral vision. She found out she had multiple sclerosis shortly after the 2010 Paralympics.
5. Matthias Lanzinger learns to ski again
Alpine skiing fans may remember Lanzinger, a former World Cup racer for Austria. Lanzinger's best World Cup finish was third in a Beaver Creek, Colo., super-G in 2005.
In 2008, he crashed in a World Cup super-G in Kvitfjell, Norway, and ended up having his left leg amputated below the knee. He returned to competitive skiing on an prosthetic leg three years later.
In 2013, Lanzinger won his first IPC Alpine World Cup gold and then gold, silver and bronze at the World Championships to set himself up for possible medals at his first Paralympics in Sochi.