According to two recent phase II trials involving panitumumab in refractory metastatic colorectal cancer (mCRC), patients exhibiting robust EGFR expression (as confirmed by IHC, with 10% of tumor cells) achieved response rates (RR) that were comparable to those with low or negative EGFR expression (with 9% of tumor cells). The gene discussed is EGFR; the disease is metastatic colorectal cancer.