Denoising Algorithm based on Relevance network Topology (DART) is an unsupervised algorithm that estimates an activity score for a pathway in a gene expression matrix, following a denoising step. In DART, a weighted average is used where the weights reflect the degree of the nodes in the pruned network. The denoising step removes prior information that is inconsistent with a data set. This strategy substantially improves unsupervised predictions of pathway activity that are based on a prior model, which was learned from a different biological system or context.