Several important findings have been made since our observation that normal human and
animal cells have a finite capacity to replicate and function. Among these are that:(1) an
inverse relationship exists betwene donor age and population doubling potential:(2) more
than 100 functional increments and decrements occur in cultured normal human cells before
they age and die;(3) normal tissue transplanted seriatim in vivo reveals a finite replicative
and functional capacity;(4) a direct relationship may exist between species maximum …