RPA1 and cancer: Again, further strengthening the hypothesis that the dependency on NUDT22 appears to be enhanced in cancer cells compared to normal fibroblasts we did not detect significantly increased DNA damage (γH2A.X) or replication stress (RPA) in MRC5-SV2 or 16HBE14o cells and this was also not enhanced by additional pyrimidine synthesis inhibition (Supplementary Fig. 5B).