In contrast, the inconsistent findings observed in experimental models may be partly attributed to CX3CR1 polymorphisms, as human variants (e.g., V249I and T280M) have been associated with altered receptor function and differential susceptibility to AD and PD (Kalinderi et al., 2012; López-López et al., 2018; Meyer, 2025). This evidence concerns the gene CX3CR1 and Alzheimer disease.