Name	Info	Provider	Link
	subscription/membership/fee required	Nature Publishing Group	https://doi.org/10.1038/nri1859
Signal regulatory proteins - overview and references	free resource	Guide to Pharmacology	https://www.guidetopharmacology.org/GRAC/FamilyDisplayForward?familyId=989
Cited by Patents in	free resource	The Lens - Patent Citations	https://www.lens.org/lens/search/patent/list?q=citation_id:16691243