Viral mimicry is a cellular state in which the reactivation of silenced transposable elements (TEs) leads to the accumulation of immunogenic nucleic acids, triggering innate immune pathways that resemble responses mounted against viral pathogens. Although they were first characterized in the context of epigenetic therapies, growing evidence indicates that other cancer treatment modalities – including radiotherapy, chemotherapies, and targeted therapies – can also induce TE reactivation and viral mimicry responses in cancer cells. This review synthesizes the current knowledge on treatment-induced TE-mediated immune responses in cancer, highlighting therapeutic strategies, shared and distinct molecular mechanisms, and their broader implications for tumor–immune interactions and treatment outcomes.

Viral mimicry is a cellular state in which the reactivation of silenced transposable elements (TEs) leads to the accumulation of immunogenic nucleic acids, triggering innate immune pathways that resemble responses mounted against viral pathogens. Although they were first characterized in the context of epigenetic therapies, growing evidence indicates that other cancer treatment modalities – including radiotherapy, chemotherapies, and targeted therapies – can also induce TE reactivation and viral mimicry responses in cancer cells. This review synthesizes the current knowledge on treatment-induced TE-mediated immune responses in cancer, highlighting therapeutic strategies, shared and distinct molecular mechanisms, and their broader implications for tumor–immune interactions and treatment outcomes.