Romance on the Set: Michael J. Fox and Tracy Pollan, who played Alex and Ellen respectively, got married in real life.
However, according to Fox's autobiography Lucky Man, the two actors did not start dating until sometime after Family Ties was cancelled, as Pollan was already dating Kevin Bacon, while Fox was dating Nancy McKeon. Fox did have a crush on her, though.
What Could Have Been: Originally, the actor who played Nick, Scott Valentine, was supposed to have been spun off into his own series, The Art of Being Nick. However, NBC did not pick it up because they were reportedly afraid that Nick's absence would hurt Family Ties.