Relevant examples include the MAPK signaling pathway, the mTOR signaling pathway, the RAS signaling pathway, the PI3K-Akt signaling pathway, the ErbB signaling pathway, the cGMP-PKG signaling pathway, the HIF-1 signaling pathway, and the cAMP signaling pathway (Figure 4A,B) suggesting that HERVs may be involved in important signaling pathways known as critical in cancer development and progression. Here, MTOR is linked to cancer.