The O'Reilly Factor | The X Factor (UK) | Microphthalmia-associated transcription factor | The X Factor | Fear Factor | Max Factor | The X Factor (TV series) | B-cell activating factor | Epidermal growth factor receptor | Psi Factor: Chronicles of the Paranormal | Astro Boy: Omega Factor | twist transcription factor | The X Factor (U.S.) | The X Factor (UK TV series) | The X Factor (UK series 2) | The Omega Factor | The Butch Factor | The Adonis Factor | Sp1 transcription factor | Rheumatoid factor | PSI Factor | O'Reilly Factor | Insulin-like growth factor 1 | Factor Three | factor | ETX (form factor) | epidermal growth factor receptor | Britain's Got the Pop Factor... | Vascular endothelial growth factor A | The Vengeance Factor |
Some of the many signalling molecules used in these pathways include the cytokines interleukin 6 (IL-6), ciliary neurotrophic factor (CNTF), and leukemia inhibitory factor (LIF).