French was displayed in the subtitles during the episode, making it the third language to be subtitled during the series, the first two being Japanese and Spanish. French was spoken in "Parasite", but no subtitles were used.

Ratings: 11.9 million viewers

DVD commentary by Greg Grunberg, Allan Arkush, and Michael Green.

Mr. Bennet: Compared to the life I had, normal's a pretty nice vacation.

Matt: You ever seen this symbol before?
Ando: Yes. It is a kanji. It means "great ability, godsend."

Kensei: (to Hiro) You look like a fish when you talk. Like a giant carp.

Mr. Zern: This video demonstrates the newt's amazing ability to regrow a completely working limb. But newts aren't the only creatures with this talent. Thanks to millions of years of combined mutation, lizards are capable of cellular regeneration.
Claire: You mean like people who can heal themselves?
Mr. Zern: Not people, Claire, lizards. And raise your hand, please.
(Claire raises her hand; Mr. Zern picks her)
Claire: But it's possible, right? For people to be able to do that, too? I mean, theoretically?
Mr. Zern: Well, there is a lot of controversial but promising work with stem cells.
Claire: So we might be able to culture whole organs and limbs for people who need them.
Mr. Zern: I guess the next step is phasing out the extra parts. We're not using our appendix anymore, or grinding bone with our wisdom teeth. We don't even really need a pinky toe for balance. It's all just junk in our DNA.
Claire: I've read that some people might have evolved a different code already. Is that possible?
Mr. Zern: I'm afraid you are going to need a degree in advanced genetics to get at those answers. And I hope you thank me in your dissertation.

Haitian: I do not want your cure.
Mohinder: Without it, you could die.
Haitian: God gave me a power. I abused his gift, so he took it away. Now I suffer his judgment.
Mohinder: Then perhaps we should leave it to God to decide.

Curandera: (to Maya) What you carry inside you is black. Enough to kill the devil.

Angela: (to Parkman about Kaito) I wasn't sleeping with him. Not for a long time.

Angela: (to Parkman, thinking) Get out of my head!

Kensei: You can make me the hero she sees in me?
Hiro: As long as you stop drinking.
Kensei: No promises.
Hiro: I can work with that.

Angela's fingerprint is found on the photograph, yet in "Four Months Later..." Angela was wearing gloves the entire episode.

Hiro: Muda muda muda muda.

The phrase that Hiro speaks is Dio Brando's, a character from JoJo's Bizarre Adventure, catchphrase. "Muda" translates as "it's useless."

Abilities Development:
Alejandro Herrera: Alejandro is able to undo Maya's power when they are near to each other. While they held hands during this episode, he brought a woman back to life that was killed by Maya.
Claire Bennet: Claire learns that she can regenerate appendages after she cuts off her small toe and it regrows in a matter of seconds.
Maya Herrera: Maya is unable to control her power, but she kills by making her victim bleed out of their eyes.
Takezo Kensei: Takezo has powers similar to Claire -- he was able to heal himself after being shot with several arrows.