Cervical cancer is caused by severe abnormal changes in the cells of the cervix. Most precancerous or cancerous cell changes occur in the cervix at the transformation zone, because these cells normally undergo constant change.
In baseball, a balk is called by an umpire. Balk rules protect runners from being deceived by the pitcher. If the ball is thrown before the batter gets settled in the batter's box, the umpire will call a balk. If a pitcher begins his delivery motion but then stops, he'll be called for a balk.
Most infractions punished as a balk: the ball is dead, no change made to the count on the batter and all runners on base advance. With no runners on base, for some infractions, the pitch attempt is automatically a ball.