Recombinant human TGF beta 3 (HZ-1090) inhibits IL-4 induced proliferation of the HT-2 mouse cell line. HT-2 cells are Balb/c spleen cells activated by sheep erythrocytes in the presence of IL-2. Cell number was quantitatively assessed by PrestoBlue® cell viability reagent. HT-2 cells were treated with increasing concentrations of recombinant TGF beta 3 for 72 hours. The EC50 was determined using a 4-parameter non-linear regression model. Activity determination was conducted in triplicate on the validated bioassay. The EC50 range is 0.14-0.75 ng/mL