Unknown—prevalence of cancer in a given organ is roughly 3% during a lung cancer trial. If the EGFR inhibitor is only effective against EGFR mutant lung cancer and they represent less than 10% of the lung cancers in a cohort of smokers than 99% of the persons will have nothing to gain during the course of such a trial. This number gets even smaller if treatment is only 50% effective even in sensitive subtypes. Here, EGFR is linked to lung carcinoma.