RIF1 and cancer: Strikingly, the usage of RIF1-S and RIF1-L isoforms in all four cancer subtypes showed the same trends: RIF1-S isoform usage was significantly increased, while RIF1-L isoform usage was significantly decreased, except in COAD, where RIF1-L isoform usage was slightly reduced, though not statistically significant (Fig. 2D).