Liquid biopsy: circulating tumor DNA monitors neoadjuvant chemotherapy response and prognosis in stage II/III gastric cancer oleh Meng Zhang, Heli Yang, Tao Fu, Meizhu Meng, Yi Feng, Changda Qu, Zhongwu Li, Xiaofang Xing, Wenmei Li, Meiying Ye, Sisi Li, Zhaode Bu, Shuqin Jia