AICDA and cancer: We can say this now because we have shown that C-site and A-site off-target ‘Ig SHM-like’ mutagenic responses mediated by DNA and RNA deaminases (adenosine deaminases acting on RNA [ADARs], activation-induced deaminase [AID] and apolipoprotein B mRNA editing catalytic polypeptide-like proteins or APOBECs) appear to be operative also across the genome during cancer progression (Steele and Lindley 2010, 2017; Lindley, 2013; Lindley and Steele, 2013; Lindley et al., 2016; Mamrot et al., 2019).