A patient doesn't want Izzie (Katherine Heigl) to treat him when he remembers her from a modeling photo.
Addison gets upset with Izzie for getting too close to the patients, as Izzie begins a relationship with heart transplant patient Denny (Jeffrey Dean Morgan).
Alex rushes her to the ER and thinks he can do her "bad patch," but Izzie knows he's in over his head.
Alex stepped up to support Izzie through her surgeries and her treatment.
An Honest Mistake - Izzie learns the truth of her condition.
As medical resident Isobel (Izzie) Stevens, Heigl has had her fair share of dramatic story lines that have won the hearts of viewers.
At the end of the episode, Izzie and George appear to meet up in the afterlife.
At the end of the season, Izzie woke from brain surgery with short-term memory issues that resolved only to leave her flatlining in the season finale.
Beat Your Heart Out - Cristina and Owen begin to truly flirt and Izzie seeks tests to learn what's wrong with her.
Before and After - Izzie uses her interns to diagnose patient X and the episode also features a crossover with Private Practice.
But Izzie's own health issues took precedence as she began seeing Denny everywhere.
Cristina, Alex, Meredith and Izzie struggled with having their own interns, medical issues and romantic woes while George struggled with the desire to take his residency exam again.
Denny woke from the transplant and seemed healthier, happier and more in love with Izzie than ever.
Derek proposes to Meredith, only to later give their wedding to Izzie and Alex when she is undergoing treatment for her brain tumor.
Fans want to know about the loves and the passions of Derek, Meredith, Alex, Izzie, Christina, Owen, Callie and even the Chief.
Fifth season episodes followed Izzie's illness and George's struggle to define himself.
Former model turned surgeon Izzie Stevens captured hearts when she fell in love with doomed patient Denny.
George and Callie get married in Vegas, and later he shares a kiss with Izzie.
George and Izzie flatlined at the same moment and viewers saw them meet in the halls of Seattle Grace.
George gets in an accident, and both he and Izzie flat line.
George was dressed in his military uniform and Izzie wore the pink prom dress from the season two finale.
He also has Izzie telling him she's in love with him.
He suffers an unexpected blood clot, and Izzie runs in, only to find a team of doctors doing the same trying to save him.
Heigl was expected to return mid-season to reprise her role as Dr. Izzie Stevens and had been in "talks" with the studio regarding her comeback.
Her whirlwind romance and marriage to George would be cannon balled by his affair with best friend Izzie.
Here's to Future Days - Mark comes face to face with a daughter he never knew and Derek prepares to do Izzie's dangerous surgery.
In one of the great turnarounds for the season, Izzie's condition deepens her relationship with Alex Karev and they share a very poignant romance complete with a fairy tale wedding.
In the 2008-2009 television season, Grey's Anatomy challenged fans when they brought the character Denny Duquette back in Izzie Stevens visions.
It wasn't so long ago when everyone fell in love with Heigl's character Izzie Stevens on the Emmy Award winning show.
Izzie and Alex grow very close, until he cheats on her.
Izzie continues to struggle with boundary issues.
Izzie found her medicinal mojo when she had to save a man with swelling using only power tools and assistance from his buddies.
Izzie gets a brain tumor, and initially doesn't want to fight it.
Izzie had spent so much time planning Meredith's wedding from her hospital bed that Meredith ultimately gave away her wedding to her ailing friend.
Izzie jeopardized her career to save Denny's life.
Izzie survived her surgery and began in earnest to return to work.
Izzie was also in love and despite resistance, she agreed to marry Denny, not even caring that her career was on the rocks.
Izzie, meanwhile, is having trouble with her patient, who needs a biopsy on a potentially cancerous testicular lump.
Izzie's diagnosis was metastatic melanoma (stage IV) and despite treatment, it had spread to her liver, skin and brain.
Izzie's storyline was all over the place after her portrayer (Katherine Heigl) complained about her storyline, and left the show for months at a time while filming movies.
Just before undergoing his heart transplant, Denny pops the question to Izzie.
Later in the season, they celebrated with a proposal and a huge wedding that Izzie wanted to arrange.
Stairway to Heaven - Izzie finally realizes that she may be gravely ill.
Stand by Me - Cristina tries to treat a resistant Izzie.
Sweet Surrender - Izzie overdoes it on her chemotherapy.
The episode celebrated with Izzie and Alex's fairytale wedding.
The first season immediately hooked viewers on the romantic trials and tribulations of Meredith, Izzie, George, Alex and Cristina.
The moment was even more bittersweet by the fact Denny seemed to be out of the woods even if Izzie sacrificed her career.
The series 100th episode aired this season featuring Alex and Izzie's wedding and the now-famous post-it note wedding occurred between series couple Meredith and Derek.
The surgery to remove Izzie's brain tumor is successful, but her memory doesn't seem to have survived intact, which Derek thinks could be temporary.
These Ties That Bind - Izzie continues to see Denny and Sadie leads the interns astray with self-teaching methods.
What a Difference a Day Makes - Izzie begins to see Denny again leading Derek to search for the cause.
What did come as a bit of a shocker is the fact that Heigl and the show's creators agreed to let Heigl and her character Izzie Stevens leave before the end of the current season.
When Izzie and Denny embarked on a sexual relationship, fans protested and the spoilers began to turn them away in droves.
When Izzie is fired, she takes off and leaves Alex.
When the organ transplant board came through, the heart was sent to Seattle Grace, but Cristina, George and Meredith had to create a wall of silence to cover Izzie's actions.
While Izzie wakes up, George doesn't and passes away.
Wish You Were Here - Izzie finally confides her problems in Alex while Cristina and Meredith feud.
You'll be able to find out everything about Meredith and Derek's emotionally-wrought relationship to Izzie and Denny's tragic pairing to Callie's controversial storyline regarding her sexuality.