1. The retrovirus infection occurs through the contact between the viral envelope and host cell wall, allowing the entry of viral RNA, reverse transcriptase and others.
2. Reverse transcriptase converts the viral RNA into DNA, which becomes integrated into cellular chromosome as a part of their normal replication cycle as Provirus.
3. This endogenous viral DNA is transcribed and the mRNA is translated into Oncogenic Proteins derived from specific sequences (Oncogene) on the viral genome.
4. Thus, normal cells are transformed into cancerous forms.