Polyomavirus encoded miRNAs. Different genomic locations of the polyomavirus encoded miRNAs have been described, but all of them are targeting the early transcript encoding the Large T-antigen (LTAg) and small T-antigen (stAg). Minor splicing variants of LTAg and MTAg (in MuPyV) are not presented. A, The alpha polyomaviruses JCPyV, BKPyV, SV40 and SA12 encode a miRNA located at the 3′ end of, and antisense to LT. Remark VP4 is included for completeness but has so far only been detected in SV40. B, MCPyV and MuPyV encode a miRNA located at the 5′ end of, and antisense to LT. C, BPCV, a virus that shares distinct characteristics of both the Polyomaviridae and the Papillomaviridae encodes a miRNA located in the second non-coding region (NCR2, indicated in pink) between the 3′ ends of the T-antigens and L1/L2.