There are scriptures in today's King James Bible and many (if not all) other versions that were not in the original manuscripts.
1 John 5:7 was an example mentioned recently in the Debate Room. Another example, also discussed in a thread a while back, is
Mark 16:9-20, which contains such nuggets as the "signs that follow", including the snake-handling and poison-drinking signs. It was added at some point, perhaps to replace the forever lost original ending of Mark's gospel. How closely it aligns with the original is anyone's guess.
I've wondered what are we to do with additions like this. Are these things (or some of them) inspired and infallible? Are they profitable for doctrine etc.? Or should they be ignored? If only some of them are infallible, which ones?