CX3CL1, also known as Fractalkine or Neurotactin, is the sole member of the CX3C chemokine family. It functions as a chemoattractant for immune cells and plays a crucial role in modulating neuron-glial signaling, inflammation, and cell-cell interactions. CX3CL1 signals through its receptor CX3CR1, and this signaling pathway is involved in multiple biological processes such as immune response, angiogenesis, and cell adhesion [1,3,5,6].

In neurodegenerative diseases like Alzheimer's, Parkinson's, and Huntington's, the CX3CL1/CX3CR1 signaling shows a complex nature. It can have neuroprotective effects by reducing the pro-inflammatory response in the CNS, but in some cases, it may promote neurodegeneration [1,4,9]. In peritoneal fibrosis, the interaction between CX3CL1 expressed on peritoneal mesothelial cells and CX3CR1 on macrophages promotes fibrosis [2]. In cancer, CX3CL1 has a dual role; increased levels can improve prognosis in some cancers but is associated with poorer prognosis in others like pancreatic ductal adenocarcinoma [3]. It is also involved in viral pathogenesis, pregnancy-related complications, and diabetic encephalopathy [5,7,8].

In conclusion, CX3CL1 is a multifunctional chemokine with a significant impact on various biological processes and disease conditions. Studies using genetic models, such as KO/CKO mouse models (although not explicitly detailed in the given abstracts), could potentially further clarify its role in these processes. Understanding CX3CL1 function provides insights into the pathogenesis of diseases like neurodegenerative disorders, peritoneal fibrosis, cancer, and more, which may guide the development of therapeutic strategies.