Football was rocked by the terrible news on Friday that Aston Villa captain Stiliyan Petrov has been diagnosed with acute leukaemia.
The disease, which a form of cancer affecting blood and bone marrow, will almost certainly mean that the Bulgarian midfielder will have to undergo a course of chemotherapy. Everyone in the world of sport and beyond is wishing him the very best as he undergoes this painful and difficult treatment.
In honour of Petrov, and in the spirit of hope and inspiration, we remember 10 other athletes who faced the worst - but came through it to be champions once again.
Lance Armstrong - Cycling
The American was one of cycling's most promising talents before he was diagnosed with testicular cancer in October 1996 aged just 25. He had won several high profile events - including the 1993 road race world championship - but his career appeared to be over as he was given a 40 per cent chance of survival. His treatment was successful and he went into remission, returning to cycling in early 1998 and going on to win seven Tour de France titles.
Magic Johnson - Basketball
The basketball legend was diagnosed as HIV positive in 1991 and briefly retired, but returned to the game the next season and ended up being named MVP in the 1992 All Star Game as well as winning Olympic gold as part of the US 'Dream Team' in at the Barcelona Games.
Bob Champion — Horse Racing
Champion was one of National Hunt racing's top jockeys, but his world came tumbling down around his ears when he was diagnosed with testicular cancer in July 1979, just a few weeks after his 31st birthday. He came through the harrowing treatment successfully and returned to the top by winning the 1981 Grand National on Aldaniti, a journey memorably chronicled in his book, Champions Story, and the subsequent film Champions starring John Hurt.
Yuvraj Singh - Cricket
The Indian batsman whose stunning displays led India to World Cup glory was diagnosed with a rare form of lung cancer earlier in 2012. He received chemotherapy treatment in the USA that finished just a few weeks ago, and the 30-year-old's prognosis is now good.
Ben Hogan - Golf
The Texan golfer was one of the finest players in the game with three Major championships to his name and a glittering career ahead of him when he and his wife were involved in a head-on crash with a bus in February 1949. Hogan dived across his wife, Valerie, to protect her and in the process avoided being impaled on his car's steering column. The 36-year-old's injuries were so severe that he was told he would never walk again, but he returned to win the US Open the following year, as well as six more Major championships including three in a season in 1953.
Alex Zanardi - Motorsport
The Italian racing driver won two CART championships in the USA and raced for F1 teams including Williams and Jordan before a horrifying crash while leading a CART race at Laustzring in 2001 saw him lose both legs. He was determined to get back into competition and in 2004 entered the European Touring Car Championship. He has continued racing ever since, and has also become a successful wheelchair marathon athlete, winning the New York Wheelchair Marathon in 2011.
Yann Kermorgant - Football
The French footballer was diagnosed with acute leukaemia aged 14 while a promising schoolboy on the books of Ligue 1 side Rennes. He didn't play again for four years, but battled back to make a life in the game and has since gone on to a successful career with sides including Grenoble, Reims, Leicester and Charlton.
Niki Lauda — Formula One
In 1976, Niki Lauda was left trapped inside his mangled, flaming wreck of a Ferrari after it swerved off the track on the second lap of the Nurburgring Grand Prix. Lauda suffered horrendous burns to his head and face and was left battling for his life over a number of days. Amazingly, though, he was back behind the wheel just six weeks later and nearly won the World Championship that year, losing by a solitary point to James Hunt.
Markus Babbel - Football
After helping Liverpool win a cup treble in 2001, Babbel was forced to take a year out of the game with Guillain-Barré syndrome - a disorder that affects the nervous system. Babble could barely use his hand or legs during that time but he fought back and he became a regular for Blackburn Rovers on loan during the 2003-04 season before returning to Germany to play for Stuttgart. He later went on to manage the Bundesliga side and is currently in charge of Hoffenheim.
Neil Harris - Football
Harris is Millwall's all-time leading goalscorer having scored 138 goals in two spells from 1998 to 2004 and then 2007 to 2011. He managed to achieve this despite being diagnosed with testicular cancer in 2001. He fully recovered a year later and he now runs a cancer charity while continuing to play for Southend United at the ripe old age of 34.