Osteopontin at the Crossroads of Inflammation and Tumor Progression

Table 1

Summary of several features of the main OPN isoforms.

	Isoform	Exons	aa differences	mRNA	Putative differences	NCBI ref seq
sOPN	OPN-a	2–7	Full length	All exons are translated	Full-length protein	NM_001040058.1
	OPN-b	2–7 Δ5	aa 59–72 are missing	Alternative splicing of exon 5	Less-phosphorylated domains	NM_000582.2
	OPN-c	2–7 Δ4	aa 31–57 are missing	Alternative splicing of exon 4	Less-phosphorylated domains + lack transglutamination signal	NM_00140060.1
iOPN	—	2–7 Δ signal peptide	aa 1–16 are missing	Downstream initiation of translation	Lack of signal peptide, intracellular localization	[73]