Fig. 1.

Scheme summarizing ErbB4 isoforms and single-pair probe design. ErbB4 isoforms are generated by alternative splicing of exons encoding the extracellular juxtamembrane domain, resulting in mutually exclusive JMa (exon 16b, light purple, 75 bp) or JMb (exon 16a, dark purple, 45 bp) isoforms, and by inclusion or exclusion of exon 26 encoding a region of the cytoplasmic domain giving rise to CYT-1 (light cyan, 48 bp) and CYT-2 (dark cyan) isoforms, respectively. Single-pair probes targeting all ErbB4 isoforms (pan 1/2, pan 2/3 and pan 27/28) are illustrated in black, whereas isoform-specific single-pair probes targeting splice junctions are color-matched with their respective isoforms. JM: juxtamembrane region; TM: transmembrane domain; CYT: cytoplasmic region