Cyclin-dependent kinase 4 and 6 inhibitors at the crossroads: the combinational therapeutic strategies in breast cancer—a narrative review

Yiqi Yang, Sha Zhu, Ziyi Fu, Chunxiao Sun, Fan Yang, Tianyu Zeng, Yijia Hua, Shengnan Bao, Xian Gao, Xiang Huang, Wei Li, Yongmei Yin