Claire Bennett (Jennifer Aniston) suffers with chronic pain and bears scars. Claire Bennet (Hayden Panettiere) was also the name of a character in Heroes whose ability was to be able to heal herself entirely.
Jennifer Aniston admitted in an interview, that she was not the first choice for the role and that she was only considered for the part, since another famous actress declined it upon reading the script. Aniston has not specified which actress originally was approached.
When Nina visits Claire in the hospital, after lighting the candles on the cake, and holding it in front of her to blow out the candles, one of the candles is out, when a new shot from a new angle appears, the candles is re-lit.