is best understood in single-celled organisms. An example is a detection and response to concentration gradients by bacteria -–the classic mathematical theory appearing in. A recent account can be found in See also Adaptor protein Scaffold protein Biosemiotics Cell signaling Gene regulatory network Hormonal imprinting Metabolic pathway Protein–protein interaction Two-component regulatory system References External links Netpath - A curated resource of signal transduction pathways in humans Signal Transduction - The Virtual Library of Biochemistry, Molecular Biology and Cell Biology TRANSPATH(R) - A database about signal transduction pathways [https://www.science.org/journal/signaling Science'''s STKE - Signal Transduction Knowledge Environment], from the journal Science'', published by AAAS. UCSD-Nature Signaling Gateway, from Nature Publishing Group LitInspector - Signal transduction pathway mining in PubMed abstracts Huaxian Chen, et al. A Cell Based Immunocytochemical Assay For Monitoring Kinase Signaling Pathways And Drug Efficacy (PDF) Analytical Biochemistry 338 (2005) 136-142 www.Redoxsignaling.com Signaling PAthway Database - Kyushu University Cell cycle - Homo sapiens (human) - KEGG PATHWAY Pathway Interaction Database - NCI Literature-curated human signaling network, the largest human signaling network database Cell biology Cell signaling Neurochemistry