Fig. 2

Human tumor viruses can control cellular plasticity to promote stemness, subvert the host immune system, and create long-lasting infections. Different human tumor viruses’ strategies for establishing latency include: While RNA tumor viruses are either transcribed into DNA with subsequent integration into the host genome or stay in the cytoplasm with no integration, DNA tumor viruses either integrate into the host genome or remain episomally, anchoring to the host chromosome. By producing several powerful oncoproteins, oncoviruses cause cellular homeostasis to be dysregulated, which results in the immortalization of the infected cell. Viral oncoproteins influence cell signaling pathways and escape from cellular defense mechanisms, such as inhibiting apoptosis, to promote abnormal cell growth. The subsequent inhibition of cellular metastasis suppressor proteins causes initial malignant cells to spread [34, 35]