Fig. 1: Schematic representation of selected FGFR2 isoforms.

Shown is the genetic structure of the two principal isoforms NM_000141.4 = FGFR2 IIIc and NM_022970.3 = FGFR2 IIIb expressed by mesenchymal and epithelial cells, respectively. Both isoforms differ only by the use of an alternative eighth exon (highlighted in red) that alters a part of the third immunoglobulin (Ig)-like domain. The isoform NM_001144913.1 represents a variant of the FGFR2 IIIb isoform lacking the first exon and using a shorter alternative last exon which leads to a shortened C-terminus also known as C3 terminus (highlighted in red). Blue bars and numbering on each isoform depict the encoded exon, where dark blue indicates coding sequences and light blue untranslated regions. At the bottom, a representation of 26 described exonic regions is displayed in black. Exons highlighted in yellow indicate that alternative exon regions exist at this genomic position. The lines connecting the exons represent the corresponding intronic regions but scaled down to 15% of the original length for illustrative purposes.