Table 4.

Betweenness Centrality properties for different human PINs

Protein interaction network	Nodes examined	Average BC (per protein)	Maximum BC
full PIN -spoke	all	21663.7	6930614.5
	Drug targets only	47319.8	6930614.5
	Non-drug targets only	19545.3	5195198.1
	B nodes only	23985.2	6930614.5
	N nodes only	46165.3	6930614.5
	S nodes only	43327.2	6930614.5
BioGRID subnetwork	all	13704.3	4436940.8
Rual+Stelzl subnetwork	all	5960.5	506957.4

BC behaves similar to degree in the sense that drug targets have higher centralities than non-drug targets, and in the sense that BioGRID and Rual-Stelzl display smaller values in comparison with the consolidated data set. However, a difference appears regarding interaction type, where nodes belonging to n-ary interactions (N and S nodes) are more central than nodes belonging to binary interactions.