Table 3. List of seven high-potential candidate proteins for PTC biomarkers.

Swiss-Prot		Gene name	Protein Name	Classical secretion	Nonclassical secretion	Membrane protein	HPPPa	ExoCartab
ID_HUMAN	Code
NPC2c	P61916	NPC2	Epididymal secretory protein E1	V
CATC	P53634	CTSC	Dipeptidyl peptidase 1	V				V
AGRINc	O00468	AGRN	Agrin	V				V
GPNMB	Q14956	GPNMB	Transmembrane glycoprotein NMB	V		V
DPP4c	P27487	DPP4	Dipeptidyl peptidase 4	V		V	V	V
ERAP2	Q6P179	ERAP2	Endoplasmic reticulum aminopeptidase 2		V
SH3L3	Q9H299	SH3BGRL3	SH3 domain-binding glutamic acid-rich-like protein 3		V			V

^aProteins were detected in the Human Plasma Proteome Project (HPPP) database, which contains 3020 proteins.

^bProteins were detected in the human exosome protein database of ExoCarta.

^cThe proteins were previously reported as potential PTC biomarkers.