The official cast photo released on May 3 2017 is a near exact recreation of the "Runaways" Vol. 1 comic book cover.
In the comics, in order for Nico's magic to work, Nico must make a blood sacrifice by making herself bleed by any means necessary (mostly by cutting herself). But in the show, it was changed to having Nico pricking her thumb on a needle in the staff, reading her DNA in the process. This was done to avoid controversy about self-harm, which is seen as a response to another teen drama, 13 Reasons Why (2017).
Ariela Barer (Gert Yorkes) used a wig in every episode except for the pilot, where she just dyed her hair purple.
Tina Minoru, the mother of Runaway Nico Minoru, appears in a prelude tie-in comic to Doctor Strange (2016) and the film itself portrayed by Linda Louise Duan.
In the comics, Molly is a mutant who eventually makes ties with the X-Men. In the series, the nature of her powers are left ambiguous because the film rights to X-Men and mutants are owned by 21st Century Fox. However, on December 14th, 2017 while the first season was airing, Disney announced their intentions to purchase Fox's film rights which include the X-Men and Fantastic Four.