NCIS star Mark Harmon has a very famous niece that you'll definitely recognize her!?

The actor has enjoyed an illustrious career, appearing in various major films and TV shows over the years. But did you know he's not the only famous face in his family?While fans of the star may know that he comes from a very well-known family, they may not realize that he is related to actress Tracy Nelson, who is Mark's sister, Kristin Nelson's daughter. 

news flash