FGF10 is a secreted fibroblast growth factor involved in developmental signalling between tissues. Its interaction with the FGFR2b isoform of FGFR2 can regulate epithelial outgrowth and organ formation. The response depends on receptor availability and the local signalling environment. A secreted ligand can therefore change tissue growth without acting as a structural component of the growing organ. ^[ref]

FGFR2 is a receptor tyrosine kinase in the fibroblast growth factor receptor family. Ligand-dependent activation connects an extracellular signal to intracellular phosphorylation pathways that influence development and cellular behaviour. Alternative receptor isoforms differ in ligand recognition; FGF10 is a ligand for the epithelial FGFR2b isoform. Thus expression of the generic receptor name alone does not specify every ligand response. ^[ref]

A secreted signalling protein with roles in endothelial development and vascular morphogenesis.

A membrane–cytoskeleton linker studied in organization of prospective vascular luminal surfaces.

A member of a family of heavily glycosylated surface proteins involved in specialized membrane organization, including the developing vascular lumen.

A protein that binds particular carbohydrate features. A lectin stain reports accessible binding sites rather than every molecule in a cell wall.

A protein–DNA interaction is physical association between a protein and DNA. Contacts can depend on base sequence, DNA shape, charge or interactions with other bound factors. A transcription factor can recognize selected regulatory sites, while histones package much larger fractions of the genome. Detecting association establishes contact or proximity under the assay conditions; regulation, bending or bridging requires additional functional or structural evidence. ^[ref]

Persistence of a pre-existing protein after its gene is removed or its synthesis stops. A late mutant phenotype can therefore lag behind the time when the gene normally acts.

A secreted antagonist involved in early embryonic signalling, including anterior visceral endoderm function in mouse.

A secreted antagonist of Nodal-family signalling expressed in developmentally restricted domains.

A secreted antagonist of canonical Wnt signalling important in developmental patterning.

A nuclear transport factor carrying suitable precursor microRNA hairpins into the cytoplasm.

Transport is coupled to the Ran nucleotide system, with different binding conditions in nucleus and cytoplasm helping release cargo on the appropriate side. Export is one step of microRNA biogenesis rather than a direct measure of final target repression. ^[ref]

A programming language whose program is an ordered list of positive rational numbers. Starting with a positive integer, multiply by the first listed fraction that produces an integer, then repeat; halt if none applies. Encoding registers as prime exponents relates this operation to a register machine.

A list comprehension constructs a list by applying an expression to elements selected through generators and optional predicates. In Python, [x*x for x in range(5) if x % 2 == 0] gives [0, 4, 16]. The generator sets the traversal, the predicate filters values and the expression transforms those retained. Nested generators preserve an order, so changing them can change output order and termination for infinite inputs in lazy languages. A Python list comprehension constructs the whole result eagerly; a generator expression instead produces values on demand.^[ref]

Polybutadiene is a polymer derived from 1,3-butadiene. Different addition modes produce cis-1,4, trans-1,4, or 1,2-containing structures, with different spatial arrangements and remaining double bonds.

This microstructure strongly affects flexibility, crystallization, and elastic behavior. The monomer name alone therefore does not specify a unique polymer chain geometry or one set of mechanical properties.

lignin is an aromatic plant-wall polymer that contributes to mechanical and chemical resistance. It can obstruct access to cellulose and adsorb enzymes nonproductively.

Polypropylene is formed from propene. Head-to-tail insertion gives the repeat connectivity $-\mathrm{C}{\mathrm{H}}_2-\mathrm{CH}(\mathrm{Me})-$. The stereochemical sequence of its substituted carbons determines its tacticity.

Tacticity describes the stereochemical ordering of configurational units along a polymer chain. It is distinct from the head-to-tail or head-to-head connectivity described by regioselectivity.

The fraction of measured material assigned to polymer under a stated separation or detection criterion. For corrected pellet and supernatant measurements, $f_P=P/(P+S)$; the assignment is valid only if sedimentation separates the intended species.

A sulfur-chain polymer with local S–S sigma bonds and filled nonbonding electron pairs. These features do not supply a partially filled delocalized conduction band.