A particularly high abundance of Illumina reads mapping to this region, and exclusive mapping of REPLI-g reads, is a likely indicator of an actively replicating viral infection since the 26 S rRNA can only be transcribed from a full-length, negative sense RNA intermediate that itself can only be produced from the nsP1/nsP4 enzyme complex required for replication50. This evidence concerns the gene SH2D3A and viral infectious disease.