ABSTRACT
Until the last decade, traditional clinical care andmanagement of complex diseases mainly relied
on different clinico-pathological data, such as signs and symptoms, demographic data, pathology
results, and medical images. In addition, efforts have been made to capture genetic factors by ex-
amining the family history of patients. The effect of such clinical and histo-pathological markers is
assessed by cohort-based studies conducted on large populations [115] and the knowledge obtained
from these studies is summarized in clinical guidelines for the diagnosis, prognosis, monitoring,
and treatment of human disease, e.g., NPI [50] and Adjuvant! Online [56, 119] for breast cancer
and palmOne [12] for prostate cancer. However, this approach still falls short. For example, there
are adverse drug reactions for some patients who have risk factors similar to those patients who
have been cured by the same therapeutic treatment. This issue stems from the strategy of one drug
fits all and motivates the need to improve on conclusions drawn from cohort-based studies so that
the underlying mechanism of complex diseases can be understood at the individual patient level.
