Proteins and peptides that are involved in SIGNAL TRANSDUCTION within the cell. Included here are peptides and proteins that regulate the activity of TRANSCRIPTION FACTORS and cellular processes in response to signals from CELL SURFACE RECEPTORS. Intracellular signaling peptide and proteins may be part of an enzymatic signaling cascade or act through binding to and modifying the action of other signaling factors.

Synonyms: Signaling Peptides, Intracellular, 0, Peptides, Intracellular Signaling, Intracellular Signaling Peptides, Intracellular Signaling Peptides and Proteins, Signaling Proteins, Intracellular, Proteins, Intracellular Signaling, Intracellular Signaling Proteins