STAT3 and neoplasm: The tumor microenvironment induced by Treg cells is regarded as a crucial mechanism facilitating immune evasion by tumors (Curotto de Lafaille and Lafaille, 2009) Ou et al. (2018) created hybrid nanoparticles conjugated with the tLyp1 peptide, which improved the ability of imatinib to downregulate Treg cells in the tumor microenvironment by inhibiting the phosphorylation of STAT3 and STAT5, leading to an anti-tumor effect.