Left image: Mac2 stimulates replication of pBAC-ΔMac2-REP-Rluc replicon, but Δ16-Mac2 does not (n=6). Right image: Cellular RNA was isolated for qPCR assay using primers and probes specifically recognizing SARS Nsp14 and ß-actin. The relative pBAC-REP-Rluc-related replicons RNA level was calculated as the ratio of Nsp14 RNA to ß-actin RNA. n=5. 