Case Report: Personalized diagnosis and treatment strategies for three cases of cancer of unknown primary based on molecular testing techniques - Ding, Yao; Zhou, Kexue; Fu, Kaiwen; Liao, Xingyun; Xiong, Shuanglong; Yang, Chengxiang; Hu, Mingyang; Liang, Guanzhong; Zeng, Xianghua; Li, Yongsheng; Wang, Donglin; Li, Yan (Frontiers in Oncology, 2025)