Excerpt from the gefitinib drug label:
"Gefitinib inhibits the intracellular phosphorylation of numerous tyrosine kinases associated with transmembrane cell surface receptors, including the tyrosine kinases associated with the epidermal growth factor receptor (EGFR-TK). EGFR is expressed on the cell surface of many normal cells and cancer cells. No clinical studies have been performed that demonstrate a correlation between EGFR receptor expression and response to gefitinib."
(For the complete drug label text with sections containing pharmacogenetic information highlighted, see the Gefitinib drug label PDF.)
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