However, recent data revealing episodic waves of APOBEC3 (A3) mutations in various cancer genomes (21, 23) favor a scenario in which A3A plays the main role in oncogenesis, since this enzyme is known to be upregulated through interferon (IFN) signaling in response to many cellular stress (12, 24, 25, 26), further emphasizing the long-standing observation that cancer emerges on a background of chronic inflammation (27). This evidence concerns the gene IFNA1 and cancer.