Sloan says he hasn't seen his daughter in 6 years. This is kind of a foreshadowing, as his daughter would make an appearance in a future episode.
In this episode it Dr. Mark Sloan states that his blood is Type 'O' Blood, same as Jessie's, however in the season before (Season 3) Episode 10 "Living On The Streets Can Be Murder" he gets a his blood type tested as 'AB Negative'.