Endogenous DNA damage and mutation

In humans, approximately 10(7) cells divide per second. Estimates suggest t hat spontaneous mutations arise in about a third of those cells. These muta tions arise as mistakes in DNA replication and when DNA polymerases copy da maged templates. The latter result from chemical hydrolysis of nucleoside b ases or by reaction of DNA with electrophiles or reactive free radicals gen erated during metabolism (endogenous DNA damaging agents). This article hig hlights recent discoveries and emerging opportunities in the study of endog enous DNA damage and mutation.