In Thy1 GN, PIASy and E12 were upregulated and distributed similarly in the nucleus of the glomerulus in the proliferative phase, along with increased α-SMA and TGF-β expression, suggesting that these genes were involved in the regulation of α-SMA under pathophysiological conditions in vivo, and that tight control of HLH levels and activity by PIASy is necessary to prevent uncontrolled cell proliferation and dedifferentiation. The gene discussed is PIAS4; the disease is ganglioneuroma.