2.

Retranscription of HERVs would activate the innate response of sensors (pattern-recognition receptors or PRRs) of single RNA strand (RIG1 and MDA5) in cytosol of the cancer cells. This activates the signaling pathways leading to activation of TRAF family member-associated NF-κB activator (TANK)-binding kinase 1 (TBK1) that causes induction of the IFN-regulatory factor-3 and 7 (IRF-3 and IRF-7), NF-KB-dependent gene expression and subsequent production of IFN beta. This results in transcriptional activation of interferon stimulated genes with the production of cytokines, and increased expression of MHC type I on cancer cells.