Arsenic trioxide decreases the amount and inhibits the function of regulatory T cells, which may contribute to its efficacy in the treatment of acute promyelocytic leukemia. - Xu, Wen; Li, Xiaoxia; Quan, Lina; Yao, Jiying; Mu, Guannan; Guo, Jingjie; Wang, Yitong (Leukemia & Lymphoma, 2018)