Katherine Heigl (Izzie Stevens) does not appear in this episode.

Mark: Surprise parties are hostile. They're dark. People jump out and scream at you.
Cristina: Hmm.
Mark: They never come to any good.

Bailey: Take off your shirt.
Alex: What? No. Take off your shirt!
Bailey: No, no. Just ... the kangaroo hold, it's most effective when there's skin-on-skin contact. It's usually the mom, but, you know, you're gonna have to do. I'm not kidding! Take off your shirt!

Arizona: I wanted you to understand that I run my peds unit a little differently than you may be used to. This is not general surgery in miniature. These are the tiny humans. These are children. They believe in magic. They play pretend. There is fairy dust in their I.V. bags. They hope and they cross their fingers and they make wishes. And that makes them more resilient than adults. They recover faster, survive worse. They believe. In peds, we have ... miracles and magic. In peds, anything is possible.

Meredith: (closing voiceover) They say the bigger your investment, the bigger your return. But you have to be willing to take a chance. You have to understand... you might lose it all. But if you take that chance, if you invest wisely, the payoff might just surprise you.

Episode Title: Invest in Love

"Invest in Love" comes from the song title "Let's Invest in a Little Bit of Love" by Wynn Stewart.