CX3CR1 and neoplasm: However, their functionality is often compromised within the tumor microenvironment (58).Recent studies have elucidated that miR-561-5p, which is upregulated in HCC, directly targets and downregulates CX3CL1 expression, thereby inhibiting the chemotactic migration of CX3CR1+ NK cells, promoting tumor cell survival, and facilitating pulmonary metastasis (59).