Cancer sciences have been advanced through retrospective studies on lifestyle, diagnosis, treatment, prognosis,and patient materials, such as cancer tissues, cell lines, serum and DNA.Time differences exist between the procurement and use of these materials and information in research.This time difference is an essential factor.Researchers are bound by the process of "informed consent" at the start of medical research,and the Helsinki Declaration states that "The potential subject must be informed of the right to refuse to participate in the study or to withdraw consent to participate at any time without reprisal." Informed consent was introduced as an essential process for invasive treatments of diseases, such as surgery.An invasion directly affects the body integrity of patients, so the explanation provided during a consent process must be dear and discrete.Therefore, researchers are asked to obtain consent with the explanation of a specific research project.However,materials and information obtained and collected in the past are useful in unexpected ways.For example, recent advancements in sequencing technologies have changed the field of cancer research, but this condition had not been explained decades ago to study participants.Since the discovery of oncogenes,genomic information has been an essential element in the area,and the human genome project started with the declaration of Dr.R.Dulbecco "to conquer cancers" Given the situation of our technical advancement, we need to reframe the "informed consent" process in cancer research.Two key factors should be mentioned: the responsibility of cancer researchers and the fact that informed consent does not only refer to the moment of obtaining patient consent.The Helsinki Declaration interestingly states, "The responsibility for the protection of research subjects must always rest with the physician or other healthcare professional and never the research subjects, even though they have given consent." I would like to extend this sentence to the"informed consent" process in cancer research and discuss its governance and cost.