By Maggie Shiels
Technology reporter, BBC news, Silicon Valley
A gaunt Steve Jobs at the 2008 WWDC reignited health concerns
As news breaks that Apple boss Steve Jobs has had a liver transplant, Maggie Shiels looks at what might happen as he returns to work.
Apple refused to comment on the story in the Wall Street Journal about the transplant. It said: "Steve continues to look forward to returning to Apple at the end of June. There is nothing further to say."
Analysts have speculated about what will happen and many believe he will only return part time as his six months of medical leave draws to a close.
Fresh concerns about his health were sparked over a year ago when he appeared at a major Apple conference looking frail.
His well-being has been a regular topic since Mr Jobs was diagnosed with pancreatic cancer in 2004.
Known as a very private individual, Mr Jobs refused to address rumours about his gaunt appearance which shocked everyone when he took to the stage at the company's World Wide Developers Conference in 2008.
In the face of demands from concerned analysts and shareholders and a share price that was affected by every ounce of speculation, Apple faithfully stuck to the mantra that Mr Jobs' health was a private matter.
Despite hating the attention, Mr Jobs laughed at many of the rumours
The adequacy of the company's statements during the affair is now being looked at by the US Securities and Exchange Commission.
Eventually, Mr Jobs felt compelled to address the issue and in January this year, ahead of the MacWorld conference, he issued a memo that said he was suffering from a "hormone imbalance".
A week later and Mr Jobs was opening up again, but this time to reveal that his health issues were more complex than he first thought.
In an e-mail to employees at the time he wrote: "In order to take myself out of the limelight and focus on my health... I have decided to take a medical leave of absence until the end of June."
This weekend the Wall Street Journal reported that Mr Jobs had had a liver transplant two months ago and was doing well.
Apple would not discuss the issue, a stance that concerned Rob Enderle, president of tech advisory firm The Enderle Group.
"The story has been unconfirmed by Apple and we don't have a cause of the liver failure, and that could be very important."
It is known that if pancreatic cancer re-occurs it is most likely to do so in the liver. This might have prompted the transplant but Apple has neither confirmed or denied any details.
Despite these latest revelations, Apple said Mr Jobs is on track to return to work as scheduled.
"I don't think his return will be that big a deal," Van Baker, a principal analyst with technology firm Gartner told the BBC.
The new iPhone 3GS was launched without Mr Jobs on Friday
"People will undoubtedly be happy to see him back at the helm but he has been engaged with the management team throughout his absence. People will be looking to see how healthy looking he is more than anything else come his first day. And the markets especially will be reacting if he looks awful."
Many industry watchers believe that he will only stay in the top spot for a short time.
Long-time Apple observer Leander Kahney, author of the Cult of Mac and Inside Steve's Brain, said: "I suspect he won't stay very long and will probably move into a chairman position. In the last 10 years he has set up these processes that will run like clockwork without him, with Jobs as the sort of holy ghost.
"His spirit is distilled in the way the company does things," said Mr Kahney.
Rob Enderle goes one step further.
"From what I am hearing when he does go back to work, it's not going to be full time and Apple is going to keep his workload pretty light. He may be back for a short time in a limited capacity and then some months down the line I expect he will retire."
Interest in Mr Jobs' well-being has been so fevered because he is one of the few chief executives seen to embody the essence of the company. His vision has also been closely aligned to Apple's success.
Mr Jobs is seen as a visionary, yet Apple has thrived without him
There were fears that with Mr Jobs being away that the company would suffer. The opposite has been true. Proof, said some, that there was "life after Steve".
"Apple has been preparing the world for the idea that he may not be running the company forever," said Roger Kay at Endpoint Technologies Associates.
Some believe that Apple without Steve Jobs being involved in some shape or form would be a mistake.
"He is the physical representative of the company. He is Apple's Ronald McDonald," Mr Enderle said.
"Apple is an extremely successful company that is seen to make hip products everyone wants. It always comes out with an innovative product that leads the pack and Steve Jobs is the face of that company."
In Silicon Valley, Mr Jobs is hugely respected and is rarely photographed outside of set Apple events.
"In the nerd world he is a rock star, along with the Google founders they are just like gods in the geek world," said Kathleen Hennessey, photography editor at the San Francisco Chronicle.
She said while it was not the newspaper's style to stake out someone like Mr Jobs, there would be a lot of kudos for the first person to get a decent snap of him.
"The first photograph of him back at his desk is the one everyone will be dying to see," she told BBC News.