Zhao S, Ren S, Jiang T, Zhu B, Li X, Zhao C, Jia Y, Shi J, Zhang L, Liu X, Qiao M, Chen X, Su C, Yu H, Zhou C, Zhang J, Camidge DR, Hirsch FR. Low-Dose Apatinib Optimizes Tumor Microenvironment and Potentiates Antitumor Effect of PD-1/PD-L1 Blockade in Lung Cancer. Cancer Immunol Res. 2019 04; 7(4):630-643.