RNA samples were profiled on a custom Agilent 44,000 feature microarray composed of 39,280 oligonucleotide probes targeting transcripts representing 34,266 known and predicted genes, including high-confidence, noncoding RNA sequences.

Each of the liver samples was processed into cytosol and microsomes using a standard differential centrifugation method. The activities of nine P450 enzymes (CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A4) in isolated microsomes from 398 HLC liver samples were measured in the microsome preparations using probe substrate metabolism assays expressed as nmol/min/mg protein. Each was measured with a single substrate except for the CYP3A4 activity that was measured using two substrates, midazolam and testosterone.