APEX1 and cancer: Additionally, other signaling axes, e.g., signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK), Metadherin (MTDH), apurinic/apyrimidinic endonuclease-1 (APEX1), etc., also coordinate with each other to promote cisplatin resistance in different cancers [19,20,21,22,23].