Control of cell cycle length and time of exit are expected to modulate the nature and extent of the neural progenitors. Intrinsic genetic programs and extracellular signaling cues contribute to the expansion of neural progenitor pool. Transcriptional factors provide key intrinsic control, qualitatively directing cell fate specification and differentiation. For example, Pax6 is required for the multipotent state of the retinal progenitors. Retnal Coloboma is known for PAX2 Production

PAX2 has no effect on proliferation of embryonic kidney or in cultured kidney cells. Our observations imply a direct role for PAX2 in survival of ureteric bud cells....Development of the mammalian metanephric kidney begins early in fetal life when the ureteric bud emerges from the Wolffian duct and grows outward in response to trophic signals from adjacent metanephric mesenchyme.1 From its inception, the ureteric bud expresses PAX2, a gene belonging to the PAX family of transcription factors which share homologous DNA-binding paired domains and influence the patterns of tissue-specific development. As the ureteric bud penetrates naive mesenchyme, it continues to express PAX2 but responds to local signals and begins to undergo extensive branching as growth continues. In this report, we provide evidence for the hypothesis that PAX2 serves a critical anti-apoptotic function in developing murine kidney collecting duct. Heterozygosity for a null PAX2 mutation produces striking apoptosis of collecting duct cells in embryonic 1Neu mice without affecting markers of proliferation. In cultured murine collecting duct (mIMCD-3) cells, we show that inactivation of endogenous PAX2 expression greatly increases apoptotic cell death; conversely, PAX2 has no effect on proliferation of MDCK cells derived from mature collecting duct. We also demonstrate that cultured human embryonic kidney cells (HEK293) lacking endogenous PAX2 are relatively protected from caspase-2-induced apoptosis when transfected with a PAX2 expression vector. source

The use of these protiens and peptides help with organ trafficing and vaccine and drug production. Is this the reason that M McC was trafficed? Please contribute to this thread