CDKN2A and neoplasm: Although tumour formation was markedly reduced in both the Low- and High-Arf groups (Fig. 3a,b), the High-Arf group acquired significantly higher tumour resistance than the Low-Arf group; 56.25% of High-Arf group mice survived ≥14 weeks without detectable tumours and 7 of 42 injection sites (16.67%) of High-Arf group mice developed tumours (Fig. 3c, Supplementary Fig. 7d).