the results demonstrate that igf-i is dispensable beyond the r-point ( 2-3 hours before s phase ) , the time when serum factors are no longer necessary for the initiation of dna synthesis , and that igf-i regulates transcriptional events necessary for both dna synthesis and the induction of thymidine kinase and in vivo thymidylate synthase .
C0598312
dna synthesis
C0040085
thymidylate synthase