Life cycle of the HBV showing the major virus-specific events, including ccc DNA generation in the nucleus from genomic DNA and its subsequent processing into viral mRNAs. The pregenomic RNA is also the template for a 2.2 kb spliced RNA that encodes the HBV splice protein (HBSP). The 2.2 kb RNA is packaged and reverse transcribed in trans by HBV Pol. Reverse transcription occurs within the core structure in replication complexes, composed of nucleocapsids in the cytosol. The envelope proteins subsequently assemble around the nucleocapsids to form mature virions.