Table 1. Number of interactions, distinct sequences and Pfam domains obtained from the IntAct, MINT, DIP, HPRD, BioGRID, STRING, and SIFTS (all releases as of February 2017.

	Number of
	PPIs	Protein Sequences	Associated Pfams
IntAct	411,624	76,747	9,898
MINT	67,191	24,735	6,438
DIP	53,585	20,489	6,418
HPRD	38,943	9,199	3,985
BioGRID	744,665	36,260	6,476
STRING	24,185,620	324,767	10,320
SIFTS	27,204	23,414	6,968