TP53 and cancer: In addition, enhanced heme synthesis and heme accumulation in tumors is also likely intended to support the activity of other specific hemoproteins not related to OXPHOS [5], or to regulate specific transcription factors with known implication in cancer, as the tumor protein P53 (TP53) [16], the BTB Domain and CNC Homolog 1 (BACH1) [17,18,19], and the nuclear factor erythroid 2–related factor 2 (NRF2) [17].