That was over 23 years ago in 1998.
Today she is 53, and has starred in 39 movies in total, 34 since The X Files was released.
In The X Files, I think Gillian Anderson looks:
The X Files scores 6.6 out of 10 on The Movie Database.
Gillian Anderson's first acting role was as 'April Cavanaugh' in The Turning, released in 1992 when she was 23.