Determination of CXCL13 in CSF appears to be a promising additional parameter for the diagnosis of early neuroborreliosis in addition to antibody determination, especially in cases where the antibody response is still negative and general parameters, such as pleocytosis and the albumin ratio, provide insufficient definitions for the diagnosis of neuroborreliosis [49,61,62]. This evidence concerns the gene CXCL13 and Lyme disease.