This dataset contain measurements corresponding to
baseline RNA expression levels measured from the NCI60, a set of 60
human cancer cell lines used by the National Cancer Institute
Developmental Therapeutics Program to screen anticancer agents since
1989. Details about
the experimental method and protocol can be found in the "Golub et al" entry in the protocols section.
Intensity values have been re-scaled such that overall intensities for
each chip are equivalent. This is done by fitting a linear regression
model using the intensities of all genes with "P" (present) calls in
both the first sample (baseline) and each of the other samples. The
inverse of the "slope" of the linear regression line becomes the
(multiplicative) re-scaling factor for the current sample. This is
done for every chip (sample) in the dataset except the baseline
which gets a re-scaling factor of one.