It has been demonstrated recently that ectopically overexpressed APE1 is translocated to the nucleoli of cancer cells but not normal cells to form biomolecular condensates and impairs the transcription of ribosomal DNA and results in S and/or G2/M checkpoint response; however, future experiments are needed to test whether such nucleolar phenotype by APE1 overexpression is mediated through ATM DDR signaling65,76. Here, APEX1 is linked to cancer.