Eve 6 says, "I am her, and she is me, and we are all together," which is a reference to the first line of the song "I Am the Walrus" by The Beatles. ("I am he as you are he as you are me, and we are all together").
The characters of Teena and Cindy were named after the wives of Glen Morgan and James Wong, who rewrote the original script prior to filming. Chris Carter said in The X Files Official Season 1 book and in Season 1 DVD Extras that Erika's character name was in honor of Glen Morgan first wife, Cindy, but in real life her mother is also called Cindy.
This is the first episode to mention supersoldiers, a recurrent theme in Seasons 8 and 9.
This episode was originally called "The Girls from Greenwich," a reference to the similarly themed The Boys from Brazil (1978).