Introduction

Pathway analysis is an important subfield of bioinformatics, including pathway algorithms, ontology, visualizations, databases. A pathway comprises one or more processes, each of which begins with input signals, uses various combinations of other input signals, such as cofactors, activators and inhibitors, and ends with output that exhibits functions. To discover the complex regulatory pathways and the potential characterized patterns of their components, a number of bioinformatics techniques and tools have been developed for varied purposes. They are proved to be useful in dealing with pathway data, and have been widely applied in exploring metabolism, genetic and environmental information processing, cellular processes, organismal systems, human diseases and drug development. One of the most critical issues to be solved by researchers is the development of efficient algorithms for collection, storage, modeling and deep analysis of diverse and complex pathway data. The knowledge gained can lead to comprehensive understanding of the molecular interaction and reaction networks in genomics, transcriptomics, proteomics, and metabolomics.