IL-7 shares the common cytokine γc with IL-2, IL-4, IL-9, IL-15, and IL-21 and the IL-7Rα chain with TSLP.

Binding of IL-7 to the IL-7Rα chain and γc leads to heterodimerization of these components and to juxtaposition of the intracellular signaling molecules Jak 3 and Jak 1. Phosphorylation of tyrosine residues within the cytoplasmic domain of the IL-7Rα chain and the Jak 1 molecule results in the activation of multiple downstream signaling pathways, including STAT5a and STAT5b, PI3-kinase (PI3K), and src kinases. In addition IL-7 signaling alters bcl-2 family member expression and localization, resulting in cell survival signals.