For instance, an observed response in an ALK wild‐type tumor having an unidentified MET amplification in a patient enrolled on a biomarker stratified lung cancer trial that is evaluating crizotinib therapy and the interaction of ALK‐translocated versus ALK wild‐type tumors would bias the results towards the null (a response in the biomarker‐negative group due to MET amplification). The gene discussed is ALK; the disease is lung cancer.