This journal publishes original papers covering all aspects of mechanisms, actions and structural components of cellular signalling systems. The emphasis is on effector systems, such as tyrosyl kinases, stress and ERK kinases, protein kinase C, lipid signalling pathways, cyclic nucleotide signalling processes and ion channels; the production, regulation, degradation and action of second messengers; the structure, regulation, degradation and action of receptors; guanine nucleotide regulatory proteins; the effect of cellular signalling events on the functioning, growth and differentiation of target cells in normal and pathological states and also cellular oncogenes. Within the scope of the journal, manuscripts dealing with biochemistry, protein structure, cell biology, molecular biology, pharmacology, neurobiology, molecular endocrinology and molecular oncology are welcomed. The journal also publishes short original reviews on topical subjects.