Table 1.

The DNA-Damaging Agents Ionizing Radiation and UV Light Induce Different Types of DNA Lesions Leading to Contrasting Cellular Responses.

Agent	Lesions/cell to kill 63% of cellsa	Bulky DNA lesions	DNA strand breaks	DNA repair	Inhibits transcriptionb	Induces p53	Induces apoptosisc
IR	1,000	no	yes	fast	no	yes	no
UV	400,000	yes	no	slow	yes	yes	yes

^aRef. [91].

^bRef. [71].

^cIn human fibroblasts [71].