Table 3.

Virokines that bind to ErbB receptors.

Virokine (ErbB-binding proteins)		Receptors	Related proteins
VGF	VGF (Vaccinia virus growth factor, vaccinia 19kd protein)	ErbB1 homodimer	EGF, TGFα
	CGF (Cowpox growth factor)	ErbB1	VGF EGF family
	SPGF (Smallpox growth factor)	ErbB1	VGF EGF family
	SFGF (Shope fibroma virus growth factor)	ErbB1 containing dimer	VGF EGF family
	MGF (Myxoma virus growth factor)	ErbB2/ErbB3	VGF EGF family
E5 protein	Human papilloma virus type16 E5 protein	ErbB1 ErbB4 (JM-b CYT-1)
	Human papillomavirus type6 E5 protein	ErbB1, ErbB2
	Bovine papillomavirus type1 E5 protein	ErbB1