Anelloviruses and Cancer.

This article focuses on the prevalence and potential role of human anelloviruses—specifically torque teno virus (TTV), torque teno mini virus (TTMV), and torque teno midi virus (TTMDV)—in cancer development. While anelloviruses are highly prevalent in healthy individuals, epidemiological studies show mixed results regarding their association with various cancers, including hepatocellular carcinoma, hematological malignancies, head and neck, colorectal, lung, cervical cancers, and Kaposi sarcoma. Proposed mechanisms suggest that anelloviruses may influence carcinogenesis indirectly through immune modulation, Toll-like receptor 9 (TLR9) activation, and inflammatory cytokine induction, whereas some viral proteins like TTV-derived apoptosis-inducing protein (TAIP) may have tumor-suppressive effects. The review highlights the need for further comprehensive molecular and clinical studies to clarify the direct or indirect roles of anelloviruses in cancer.