Dr. Mark Andrews is a neurologist at Princeton-Plainsboro Teaching Hospital and Chi Park's former supervisor. He was portrayed by actor Ben Lemon.
Just before the events in Transplant, a patient needed an emergency life-saving procedure that required a neurologist. Dean of Medicine Eric Foreman could only get a hold of Dr. Andrews, who had been drinking and was unable to perform it. However, he was of the opinion that Dr. Park was capable of doing it while supervised. He came to the hospital where he walked Dr. Park through the successful procedure. Unfortunately, after she successfully completed it, in his inebriated state he decided to feel up Dr. Park's behind. Dr. Park reacted by punching him, resulting in her being put on leave. Dr. Foreman had to tell the Board of Directors that Andrews was drunk and this resulted in Foreman losing two week's pay.
In Risky Business, on the day of Dr. Park's disciplinary hearing, Dr. Andrews sent out an apology to the hospital, saying that he was only trying to congratulate Dr. Park for completing the procedure, and saying he had undergone harassment training. Dr. Park thought that Dr. Andrews was taking responsibility for his conduct, but House told her Andrews was only trying to make himself look sympathetic by portraying Park as having overreacted.
Just before her disciplinary hearing on the matter, House deliberately sought out Dr. Andrews for a consult on his case, just to get under Park's skin. When they entered Andrews' office, Dr. House pretended that he didn't know Andrews and Park knew each other. He also deliberately made sexist remarks about Park to embarrass both Park and Andrews. House then deliberately sided with Andrews to further enrage Park, who went ahead and ignored House. Jessica Adams agreed to do the test to confirm Park's diagnosis while Park prepared for her hearing.
However, after the patient went into a coma, House admitted to Adams that he thought Andrews was an idiot and started looking for other diagnoses. He then broke in on Park's hearing and threatened to fire her. The combination of factors broke down Park's tough exterior in front of the hearing committee, making her look like the vulnerable young woman she was rather than the tough minded woman she tried to portray. The board realized her reaction to Andrews' fanny pat wasn't deliberate and allowed her to keep working.