NFE2L2 and head and neck cancer: Nuclear factor (erythroid-derived-2)-like 2 (NRF2) is a transcription factor that is known to play a pivotal role in the pentose phosphate pathway (PPP) of glioblastoma (31), breast cancer cells (32), head and neck cancer (26), human hepatoma cells (33), and colon cancer (34) and to affect cell metabolic reprogramming.