PD-1 downregulation enhances CAR-T cell antitumor efficiency by preserving a cell memory phenotype and reducing exhaustion ========================================================================================================================== * Wanyan Ouyang * Shi-Wei Jin * Nan Xu * Wei-Yang Liu * Han Zhao * Liuqingqing Zhang * Liqing Kang * Yi Tao * Yuanfang Liu * Yan Wang * Jin Wang * Feng Liu * Lei Yu * Zhiqiang Liu * Jian-Qing Mi