CD4 and neoplasm: Tregs significantly increased the inhibition of CD8+ and CD4 (+) T cell proliferation and cytokine secretion, and increased numbers of circulating CD4 (+) CD25 (+) Foxp3 (+) Tregs and tumor-infiltrating Foxp3 (+) cells prior to cryoablation were associated with a higher risk of recurrence or progression in HCC patients after cryoablation.