Whatever Happened to ‘Step By Step’ Star Christopher Castile?
Then: Christopher Castile played the brainy fanny-pack wearing nerd Mark Foster on ‘Step By Step.’ He was also well known during that time period for his role as Newton family son Ted in ‘Beethoven’ and ‘Beethoven’s 2nd,’ as well as providing the voice of Eugene Horowitz on the Nickelodeon series ‘Hey Arnold.’ All of these characters were (shocker!) also huge nerds. So what happened to him?


