Table 2. Potential viral proteins triggering carcinogenesis.

ACE2: angiotensin-converting enzyme 2; TMPRSS2: transmembrane serine protease 2; ATGIIR1: angiotensin II receptor-1

Protein/ Molecule	Role in Carcinogenesis	Key Mechanism	Relevant Cancer Types
ACE2 [65-68]	Downregulation due to SARS-COV-2 infection may increase AGTII levels, promoting tumor growth via the ATGIIR1 pathway.	Facilities tumorigenesis by promoting angiogenesis and cellular proliferation	Lung, kidney, testicle, and small intestine cancers
TMPRSS2 [54]	Degrades extracellular matrix proteins, facilitating cancer cell invasion and metastasis. Overexpressed in COVID-19 cases.	Supports viral entry and possibly enhances cancer cell invasiveness	Prostate cancer, potential in other cancers through interaction with TMPRSS2
FURIN [69,70]	Promotes cell proliferation, migration, invasion, and vascularization in various cancers, overexpressed in COVID-19 cases.	Drives oncogenic processes, especially in KRAS and BRAF mutant colorectal cancer	Lung, head and neck, colon, gynecological cancers, sarcomas