CHRONOLOGY - Key dates in health saga of Apple's Jobs

Apple Inc CEO Steve Jobs displays a redesigned iPod Nano at Apple's ''Let's Rock'' media event in San Francisco, California September 9, 2008.

REUTERS - Apple Inc Co-founder and Chief Executive Steve Jobs is back at work, returning from a near six-month medical leave after receiving a liver transplant.

Here is a chronology of his health issues:

August 2004: Jobs announces he underwent successful surgery to remove a cancerous tumor from his pancreas. He said it was a rare form of pancreatic cancer called an islet cell neuroendocrine tumor.

June 2005: Jobs mentions the cancer in a commencement address at Stanford University.

"This was the closest I've been to facing death, and I hope it's the closest I get for a few more decades," he says.

2008:

June 9: Jobs appears dramatically thinner at an Apple iPhone event, touching off speculation the cancer had returned. The company said he was fighting a "common bug" and taking antibiotics. Apple later called Jobs' health a "private matter."

July 26: The New York Times journalist Joe Nocera wrote in a column that he had spoken to Jobs about his health but that because the conversation was off record, he could not disclose what was said. "While his health problems amounted to a good deal more than 'a common bug,' they weren't life-threatening and he doesn't have a recurrence of cancer," Nocera wrote.

Sept. 9: At an iPod product launch, Jobs jokes about his health by walking on stage in front of a giant screen that flashed "The reports of my death are greatly exaggerated" -- a quotation borrowed from Mark Twain.

Oct. 3: A false Internet report that Jobs had suffered a heart attack briefly pushes Apple shares down 2 percent to a 17-month low. Apple quickly denied the report on iReport.com, a citizen journalist site owned by CNN.

Oct. 14: At a Mac product launch event, Jobs jokes again about his health. His blood pressure was 110 over 70 and he said, "And that's all we're going to be talking about Steve's health today."

Dec. 16: Apple said Jobs won't deliver the keynote address at the Macworld trade show in January, reviving concerns about his health. Asked to explain the decision, a spokesman said it would be the last time Apple takes part in Macworld so "it doesn't make sense for us to make a major investment in a trade show we'll no longer be attending."

Dec. 30: Apple shares fall as much as 2 percent after Gizmodo reported that Jobs health was "rapidly declining" and that was the reason why he canceled the Macworld keynote.

2009:

Jan. 5: Jobs says he has been losing weight throughout 2008 and his doctors think a hormone imbalance was "robbing" him of proteins. He says he has begun a "relatively simple and straightforward" treatment for his nutritional problem and that he will continue as CEO during recovery.

"I will be the first one to step up and tell our board of directors if I can no longer continue to fulfill my duties as Apple's CEO," he says. Apple shares rise 5 percent.

Jan. 14: Jobs announces medical leave until the end of June, saying his health issues are "more complex" than originally thought. He hands day-to-day operations to Chief Operating Officer Tim Cook and says he plans to remain involved in major strategic decisions. Apple shares fall 10 percent in after-hours trading.

Jan. 21: The U.S. Securities and Exchange Commission is examining Apple's disclosures about Jobs to ensure investors were not mislead, Bloomberg reports.

June 8: Apple unveils new iPhone 3GS at its annual Worldwide Developer's Conference, but Jobs does not make an appearance.

June 20: The Wall Street Journal reports that Jobs had a liver transplant in Memphis, Tennessee about two months ago and that he is expected to return to work later in June.

June 22: Jobs is spotted at the Apple campus in Cupertino, California, underscoring expectations that he is either back at work or will return soon.

June 23: The Methodist University Hospital Transplant Institute confirms it performed a liver transplant on Jobs and says he is "recovering well and has an excellent prognosis." The hospital does not give more details, saying the confirmation had come with Jobs' permission.

June 30: Jobs returns to work, an Apple spokesman says. adding that he will work from home part of the time.