The effects of transforming growth factor-β (TGF-β) are determined by cellular context. There are three kinds of contextual factors that determine the shape the TGF-β response: the signal transduction components, the transcriptional cofactors and the epigenetic state of the cell. The different ligands and receptors of TGF-β are significant as well in the composition signal transduction pathway.
* the signal transduction components: ligand isoforms, ligand traps, co-receptors, receptor sub-types, inhibitory SMAD proteins, crosstalk inputs
* the transcriptional cofactors of SMAD proteins: pluripotency factors, lineage regulators, DNA-binding cofactors, HATs and HDACs, SNF, chromatin readers
* the epigenetic factors: heterochromatin, pluripotency marks, lineage marks, EMT marks, iPS cell marks, oncogenic marks.