Treg cells are a subset of T cells with significant immunosuppression, characterized by the expression of Foxp3, CD25 and CD4, which are related to the disease progression and poor prognosis of multiple myeloma [43, 44], lung cancer [45], hepatocellular carcinoma [46] and breast cancer [47, 48]. The gene discussed is FOXP3; the disease is hepatocellular carcinoma.