Specifically, the reduced activation of Chek1/P53 cell cycle checkpoint in response to irradiation observed in AEP KD cells (Figs. 4B and C) explains why AEP deficiency in cancer cells resulted in genomic instability and cell death, due to their inability to properly activate Chek1/P53 cell cycle checkpoint in response to DNA damage. The gene discussed is TP53; the disease is cancer.