abnormal protein level abnormal intercellular signaling peptide or protein level MP:0008835 MPheno.ontology These molecules are generally considered factors that are expressed by one cell and are responded to by receptors on another nearby cell. These are distinguished from hormones in that their actions are local rather than distal. abnormal concentration of any regulatory protein or peptide that is a signaling molecule involved in the process of paracrine communication abnormal growth factor level abnormal paracrine peptide factor level abnormal paracrine protein factor level