Cancer driver genes versus passenger genes. Two candidate genes C1 and C2 are located on an inferred CNV region, and are likely cis regulated by a CNV. To distinguish potential drivers from passengers, we test whether they can causally regulate other genes. To determine whether a downstream gene G is regulated by C1 or/and C2 or neither is equivalent to selection among four competing models. Given that many other potential genes or factors affect the expression level of gene G, the models conditioning on all other factors are needed to evaluate, i.e., a Bayesian network reconstruction process.