H2AX and infection: In NS-expressing cells, both RPA32 (replication protein A 32) and histone variant H2AX (H2A histone family, member X) were phosphorylated, as detected using antibodies against p-RPA32 (the RPA32 phosphorylated on serine 33) and γH2AX (the H2AX phosphorylated on serine 139), over the course of infection (Fig 2A and 2B), suggesting that HBoV1 infection induces a DDR.