In a further patient with a history of chronic viral meningitis of unknown cause (previous WCC: 186 [2017], 49 [2018] and 83 [2019] cells/μl), COVID-19 and headache, WCC, OCB, QIgG/IgA/IgM and QAlb were all normal; only CSF TP was elevated, albeit markedly so (295 mg/dl; compared with a median of 41.75 mg/dl in group I [all ≤ 240 mg/dl; 95% ≤ 160]). This evidence concerns the gene CD40LG and viral meningitis.