Interviewed at the Palm Beach Cancer Symposium, John Macdonald, Chief Medical Officer of Aptium Oncology in Los Angeles, talks about his latest data on the relevance of KRAS tumor status—i.e., whether the gene is wild-type or mutant determines the sensitivity of the tumor to anti-EGF or anti-VEGF receptor therapy. He also discusses the disappointing finding that blocking both of these proliferation pathways does not lead to improved efficacy when two targeted drugs are used in combination.