This is the first episode where Madrigal Electromotive is mentioned. It is seen on the bottom of the screen of the Los Pollos Hermanos commercial "Los Pollos Hermanos, INC. is a registered trademark of Madrigal Electromotive GmbH."
During the one-on-one table conversation between Walt and Gus, the light shines in to only show one half of their face on every shot, giving the impression that both men have other personalities.
Hank's doctor tells Marie the same thing Walt's oncologist told the family in season two: manage your expectations.
This has four Seinfeld (1989) alumni: Bryan Cranston, Anna Gunn, Bob Odenkirk and Mark Harelik (AKA Milos the lousy tennis player), who plays the doctor in this.
Although he appears, RJ Mitte (Walter White, Jr.) has only one line in this episode: "Man he got you good!"