FOXP3 and neoplasm: Other research reveals that the proportion of circulating regulatory T (Treg) cells is related to the level of CA125 in the serum, and the C-terminal of MUC16 can activate the JAK2/STAT3 signaling pathway triggered by tumor-secreted IL-6, promoting the expression of Foxp3 and the accumulation of tumor-associated Tregs in pancreatic cancer (37).