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In signaling pathways, stimuli are transmitted via a cascade process to yield the correct and appropriate response. Examples of cell signaling pathways include lipid signaling, insulin signaling, stress signaling, growth signaling, TOR signaling, and checkpoint signaling. 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[Shop Products](https://www.sigmaaldrich.com/US/en/products/protein-biology/bioactive-small-molecules/structural-genomics-consortium) * * * Related Articles & Protocols Support ## Related Articles - [DNA Damage Response (DDR) Pathway](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/research-and-disease-areas/cancer-research/dna-damage-response-ddr-pathway) Explore key targets of cancer research and cell signaling research with the DNA damage response (DDR) pathway and do a deep dive into ATM, ATR, and p53 mechanisms involved in DNA damage checkpoints. - [Lipopolysaccharides](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/research-and-disease-areas/cell-signaling/lipopolysaccharides) Lipopolysaccharide (LPS) is a major component of Gram-negative bacteria, important for microbiological research. - [Acetylcholine Synthesis and Metabolism](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/research-and-disease-areas/cell-signaling/acetylcholine-synthesis-and-metabolism) Acetylcholine is synthesized from acetyl coenzyme A and choline by the enzyme choline acetyltransferase. In addition to its synthesis in the liver, choline employed in acetylcholine production is derived from dietary sources. - [Tissue Dissociation Guide: Collagenase, Dispase, and Liberase Enzyme Types](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/research-and-disease-areas/cell-signaling/collagenase-guide) Collagenase Guide.Collagenases, enzymes that break down the native collagen that holds animal tissues together, are made by a variety of microorganisms and by many different animal cells. - [Glycosaminoglycans and Proteoglycans](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/research-and-disease-areas/cell-signaling/glycosaminoglycans-and-proteoglycans) Uncover more about glycosaminoglycans and proteoglycans including the structure of glycosaminoglycans (GAGs), the different types of GAGs, and their functions. - [See All (112)](https://www.sigmaaldrich.com/US/en/search/facet-search?focus=sitecontent&term=facet-search) ## Related Protocols - [Assay Procedure for Protease](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/protein-biology/enzyme-activity-assays/assay-procedure-for-protease) This procedure is for informational purposes including assay Procedure, definition, and calculations for Protease - [Ion Channel Flux Assays and Protocols](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/research-and-disease-areas/cell-signaling/ion-channel-flux-assays-and-protocols) A review and resources for ion channel flux assays and protocols, along with liposome formation and proteoliposome preparation protocols - [Assay Procedure for Cholesterol Oxidase](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/research-and-disease-areas/cell-signaling/assay-procedure-for-cholesterol-oxidase) Protocol for Assay Procedure for Cholesterol Oxidase - [Protease Fluorescent Detection Kit Usage](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/research-and-disease-areas/cell-signaling/determine-protease-activity-with-protease-fluorescent-detection) Protease Fluorescent Detection Kit detects protease activity using FITC-labeled casein substrate. - [See All (10)](https://www.sigmaaldrich.com/US/en/search/facet-search?focus=sitecontent&term=facet-search) [![Document Search](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/ecommerce/document-search.png "Document Search")](https://www.sigmaaldrich.com/documents-search) [Looking for More Specific Information?](https://www.sigmaaldrich.com/documents-search) Visit our document search for data sheets, certificates and technical documentation. 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