UBC9 and PIAS1 SUMOylate FOXL2 with SUMO1 (Kuo et al. 2009, Marongiu et al 2010, Georges et al. 2011). This modification changes its cellular localization, stability and transcriptional activity (Marongiu et al, 2010). SUMOylation localizes FOXL2 to PML bodies in the nucleus. SUMOylation is required for repression of transcription by FOXL2 at the StAR promoter and reduces transactivation by FOXL2 at the PER2 promoter. Hypophosphorylation of serine-33 correlates with SUMOylation and stablization of FOXL2, leading to enhanced transcriptional activation of TNF-R1, FAS, caspase 8, p21, and aromatase (Kim et al. 2014).