Crosstalk between interleukin signalling pathways. Protein interaction sub-network containing the proteins annotated for 7 different Interleukin (IL)-related pathways from the BioCarta database (each colour represent a pathway, proteins annotated for multiple pathways display more than one colour). Proteins added by our method are highlighted by surrounding circles and coloured according to the pathway(s) they were added to (they appear mostly within peripheral clusters or as links between process members). They were not annotated for any of the IL-related pathways before applying the extension procedure, and the original pathway members did not become members in further IL-related pathways. Therefore, to simplify interpretation and provide a compact data representation, the node colours are only used to visualise the pathway memberships after the application of the extension procedure.