Evidence suggests that cytokines such as interleukin-1β (IL-1β), IL-6, interleukin-7 (IL-7), interleukin-8 (IL-8), interleukin-11 (IL-11), tumor necrosis factor-alpha (TNF-α), TGF-β, and C-C motif chemokine ligand 12 (CCL12) play significant roles in the bone metastasis of lung cancer (43–46). Here, IL7 is linked to lung carcinoma.