It was once believed that cells grown in laboratory tissue cultures were essentially immortal  That is, as long as all of their needs were met, they would continue dividing forever  However, it has been shown that normal cells have a finite reproductive limit  A human liver cell, for example, divides 60 times and then stops  If such a cell divides 30 times and then is put into a deep freeze for months or even years, it remembers where it stopped dividing
After thawing, it divides another 30 times -- but no more
a normal human liver cell that had been frozen after its first division and afterward thawed