[R] look for packages Dear list members,

I am analysing some microarray data. I have got the differentially
expressed genes and now want to carry out PCA analysis to get the main
components that contribute to the variance.I have browsered the CRAN and
BioConductor and did not find an appropriate package.

Have anybody ever carried out PCA analysis? Is there any package about PCA
in R?

Thanks for your advice.

