GINS4 and breast cancer: Based on the correlations described above, we aimed to study the relation between ADAR1 activity and the expression or stability of ATM, GINS4 and POLH. To address this, a ZR-75-1 BC cell line was transduced with a lentivirus coding for a short hairpin RNA against ADAR1 (ZR-75-1 SHADAR) or a scrambled sequence (ZR-75-1 SHC).