CXCL10 and viral infectious disease: We, and others, have found that, among several interleukins and chemokines, CXCL10 (interferon-γ-inducible protein-10 or IP-10), a well-known chemokine [32, 33] that recruits immune cells expressing CXCR3 [34] and contributes to lung inflammation in several viral diseases [35, 36], correlates with the extent of SARS-CoV-2 viral replication in the tissues and is a strong marker of COVID-19 disease severity [27, 37, 38].