Breast milk cytokines have the potential to regulate the immune response to food antigens in infants. Cytokines are present in all mammalian milks and are capable of inhibiting excess inflammation and modulating epithelial proliferation. There are a range of candidate cytokines in milk such as transforming growth factor-β (TGF-β), the major cytokine present, and interleukin-10, which play a role in immune regulation in the developing infant. This article will be a review of the current literature with regard to TGF-β in infant immune development. Our data on supplementation of formula with rTGF-β2 will be discussed in view of the current literature. Oral antigen exposure also plays an important role in priming the developing immune response. The influence of early introduction of oral β-lactoglobulin in allergy prone rat pups will also be discussed.