Over the course of Grey’s Anatomy‘s 21 seasons, many characters have come and gone, including Sandra Oh’s Cristina Yang, but the possibility of her return is now higher than ever. Given the nature of the ABC medical drama, doctors filter in and out of Seattle Grace Hospital/Grey Sloan Memorial Hospital quite often. Now, with Grey’s Anatomy in its 21st season, none of the original characters remain,aside from Ellen Pompeo’s Meredith Grey, but even her role is limited. Many have died or moved away, like Cristina at the end of season 10.