PPIA and hepatitis A virus infection: Cyclophilin A has been found in maturevirions of HIV and is known to play a key role in the replicationof HIV, hepatitis B, and other coronaviruses27 Interestingly, the interaction between cyclophilin A and the HIVcapsid protein is known to be conformation-dependent;36 we anticipate such parallels with SARS-CoV-2 and speculatethat other N proteoforms do not interact with CypA because of a conformationalchange or restricted access to the interacting domains.