![](https://webarchive.library.unt.edu/eot2008/20081024144708im_/http://www.nci.nih.gov/images/spacer.gif) |
¿Preguntas sobre el cáncer?
![](https://webarchive.library.unt.edu/eot2008/20081024144708im_/http://www.nci.nih.gov/images/spacer.gif)
|
1-800-422-6237
(1-800-4-CANCER)
|
![](https://webarchive.library.unt.edu/eot2008/20081024144708im_/http://www.nci.nih.gov/images/spacer.gif)
|
Llame de lunes a viernes de 9:00 a.m. a 4:30 p.m., hora local en Estados Unidos y sus territorios. |
|
![](https://webarchive.library.unt.edu/eot2008/20081024144708im_/http://www.nci.nih.gov/images/spacer.gif) |
|
![](https://webarchive.library.unt.edu/eot2008/20081024144708im_/http://www.nci.nih.gov/images/spacer.gif)
![](https://webarchive.library.unt.edu/eot2008/20081024144708im_/http://www.nci.nih.gov/images/spacer.gif)
| Sustancia química muy reactiva que suele contener oxígeno y que se produce cuando las moléculas se separan para generar productos con electrones no apareados (proceso que se llama oxidación). Los radicales libres pueden dañar importantes moléculas celulares como el ADN, los lípidos u otras partes de la célula. |
![](https://webarchive.library.unt.edu/eot2008/20081024144708im_/http://www.nci.nih.gov/images/spacer.gif)
![](https://webarchive.library.unt.edu/eot2008/20081024144708im_/http://www.nci.nih.gov/images/gray_spacer.gif)
![](https://webarchive.library.unt.edu/eot2008/20081024144708im_/http://www.nci.nih.gov/images/spacer.gif)
|
![](https://webarchive.library.unt.edu/eot2008/20081024144708im_/http://www.nci.nih.gov/images/spacer.gif) |