The invention relates to methods for determining whether a peptide is capable of modulating signalling via at least one Pattern Recognition Receptor (PRR) signalling pathway and/or G protein coupled receptor (GPCR) signalling pathway, the method comprising providing a cell susceptible to signalling through at least one of said pathways, contacting said cell with at least one dipeptide, contacting said cell with an agonistic or antagonistic compound of a PRR and/or a GPCR of said pathway, and determining the activity of said at least one signalling pathway in said cell. The invention further relates to use of peptides in therapeutic applications where modulation of at least one PRR and/or GPCR signalling pathway is desirable.
