Folate receptor-positive circulating tumor cells as a predictive biomarker for the efficacy of first-line pemetrexed-based chemotherapy in patients with non-squamous non-small cell lung cancer

Xiaoxia Chen, Fei Zhou, Xuefei Li, Guohua Yang, Chao Zhao, Wei Li, Fenying Wu, Jia Yu, Guanghui Gao, Jiayu Li, Aiwu Li, Shengxiang Ren, Caicun Zhou