produced, and one that has introduced integration methodologies for all available information to draw a more complete view of the biological mechanisms of the disease. Along these lines, a recently published review presents a cancer research-inspired pipeline that applies high-throughput and high-content profiling technologies integrated with omics profiling for assessing toxicity of chemicals and engineered nanomaterials. [6] The authors emphasize how, in analogy to biomarker discovery in cancer research, toxicology's aim is to identify genes or pathways from the "toxome" that could predict specific toxicity effects. Indeed, the search for new approach methodologies is largely focused on "big data" such as omics, but to this date there are relatively few concrete examples of how to utilize this type of data within the currently available risk assessment frameworks. Quantitative structure-activity relationship (QSAR) modeling remains a key method in toxicology, aiming mainly to predict the dependent variable of interest ("end-point") using structural and physicochemical data, although there are recent paradigms of successful prediction with omics data. [7,8] Grouping and read across is one of the most commonly used alternative approaches for risk assessment of novel substances and materials of industrial relevance submitted under the registration, evaluation, authorization and restriction of chemicals. Particularly, the read across method has not yet gained full regulatory acceptance, however recent efforts by the European chemicals agency (ECHA) are contributing toward its consistent and transparent evaluation.Methods for integrating biological information relative to genes' functions have been developed for omics data, [9][10][11][12] but have rarely been applied to QSAR modeling or grouping. For example, pathway analysis via gene set enrichment analysis (GSEA) methods [13] or the so-called connectivity mapping models have been applied to toxicity data to identify similar modes of action. [14,15] Smalley et al. [15] presented a connectivity mapping model to compare a query gene set microarray profile from a biological system exposed to a test substance, to those in a reference compounds database. In another approach, Williams and Halappanavar [16] identified pulmonary disease-related biclusters of genes from gene expression profiles derived from mouse disease models, which were then used to conduct GSEA The interest toward omics data is growing in the field of toxicology owing to the diverse knowledge they generate, which can improve prediction and dosage profiling for more accurate safety assessment. An integration methodology is presented where high-throughput omics data are enriched with biological-pathway information to produce a novel set of biological (BIO) descriptors by decomposing omics data to meaningful clusters in terms of both their mechanistic interpretation and correlation affinity. A generalized simulated annealing algorithm is employed to estimate the optimal partition of the enriched data and ...