RB1 and lung adenocarcinoma: Of course, we acknowledge the possibility that any DNA damage occurring after ALKBH3 silencing in lung adenocarcinoma cells may induce transcriptional factors other than p53/Rb that upregulate both p21 and p27, and we cannot deny the possibility that the ubiquitin–proteasome protein degradation pathway may be partly involved in p21, p27 induction.