Among them, we selected a clone with an 8-fold increase in the level of Polβ mRNA (clone 28) over control (AGS/CTR) together with a pool of transfected AGS clones with an average 2-fold increase in Polβ expression (indicated as Pool) that resembles what was observed in our set of gastric cancers (Supplementary Figure S1A). Here, POLB is linked to gastric cancer.