The second dataset is from a study that compared gene expression in liver from male rats fed a diet deficient in vitamin A to a control group fed the same diet plus vitamin A ("vitamin A data") [15,21]. That study used Affymetrix RGU34A GeneChips. Data for all 14 arrays are available from Gene Expression Omnibus at NCBI, accession numbers GSM27430 through GSM27443 and GSE1600.
