HSPA1A and influenza: Upon CDV infection, Hsp70 is shown a strong contribution to viral replication by interacting with and promoting the translocation of the nucleocapsid particles from the cytosol to nucleus.216 Similarly, during influenza infection, Hsp70 interacts with PB2 or PB1 monomers and PB2/PB1 heterodimer in HeLa and HEK293T cells, and sequentially translocates into the nucleus with PB2 monomers or PB2/PB1 heterodimers.217 If Hsp70 and PB2/PB1 polymerases are retained in the cytosol, the polymerase activity reduces dramatically.