RB1 and cervical cancer: In particular, all three cervix cancer subtypes exhibit frequent evidence of activating PI3-kinase/MAPK pathway mutations and only rarely carry non-silent mutations in the tumor suppressors TP53 or RB1. Among the three cervix cancer subtypes, the total coding mutational burden is similar and a substantial fraction of these mutations are related to AID/APOBEC cytidine deamination mutational processes.