CXCL13 and viral infectious disease: Recent studies reported that CXCL13 was increased in viral infectious diseases and was associated with the progression and severity of diseases, such as HIV [14], SARS-CoV-2 [13], HBV [15], influenza A virus (IAV) [11], etc. In our previous study, the elevated level in the sera of CXCL13 was related to the severity of the disease following FMDV infections, which indicated that CXCL13 plays a role in the disease progression in FMDV-infected mice [18].