ERG regulated IL-9 production in TH9 cells in the absence of PU.1 and ETV5. These experiments were performed using transgenic conditional knock-out mice including: Spifl/flEtv5fl/flErgfl/fl CD4 cre−, Spifl/flEtv5fl/fl CD4 cre+ and Spifl/flEtv5fl/flErgfl/fl CD4 cre+ respectively (n=3 per group) (A-J). (A-D) Transcript expression of Erg, Spi1, Etv5, and Il9 respectively. (E) IL-9 production in TH9 cells cultured measured via flow-cytometry. (F) IL-9 secretion measured by performing ELISA. (G-J) ChIP qPCR assay to assess interactions of PU.1, ERG, p300 and H3K27Ac at the Il9 locus in resting TH9 cells. Data are mean of three-four mice per experiment and representative of two independent experiments. *p<.05; **p<.01; ***p<0.001; ****p<0.0001.