Biomarkers are molecules found in bodily fluids or tissues (including the tumor tissue). They provide valuable information about the cancer cells and non-cancer cells when analyzing which biomarkers are produced in response to the cancer. By developing a biomarker profile of a patient’s cancer, doctors can recommend the best suited treatment plan for their patient. This insight allows patients, who are more likely to respond to a targeted drug, avoid treatments that would be less beneficial. Biomarker testing is now widely used among Canadian oncologists, but barriers to expanding their use remain.