Patricia Arquette (Allison) and Sofia Vassilieva (Ariel) both had their heads shaved for this season. This is because Sofia played a cancer-stricken girl in "My Sister's Keeper" and Patricia wanted to shave her head to support her.
This was the first episode broadcast on CBS.
When Scanlon, Devalos and Allison are leaving for a conference, Scanlon says to Allison who is now walking with a cane, "After you, Doctor House". This references the TV series House (2004), wherein the main character, Doctor Gregory House (Hugh Laurie), is never seen without his cane.