X-40253 is an X-file regarding the disappearance of Samantha T. Mulder. Information in the file includes Samantha Mulder's address of 2790 Vine Street, Chilmarc, Massachusetts and her date of birth - January 22, 1964. A photograph of Samantha Mulder as a young girl is also included in the file.
- The file gives Samantha's name as Samantha T. Mulder and her date of birth as January 22, 1964. However, a file in "Paper Clip" showed that Samantha's name was Samantha Ann Mulder and that she was born on November 21, 1965.