Isobel 'Izzie' Stevens

Growing up in a trailer park and putting her newborn daughter up for adoption at age 16, Izzie managed to progress along medical school by paying her bills through modeling. She put her career as doctor on the line in a risky bid to get her lover Denny Duquette a new heart by cutting his LVAD wires. Denny subsequently died but Izzie managed to keep her job. Izzie began a relationship with Alex Karev, but their relationship came under strain when she was diagnosed with metastatic melanoma. She survived the condition following treatment with Interleukin-2 but after restarting work she accidentally induced hyperkalemia in a patient listed for renal transplant. Subsequently she lost her job, and has since disappeared from Seattle Grace. However, her character will have a proper closure to her relationship with Alex in season 7.