CYP2A7 and cancer: Moreover, from the pool of differentially expressed CYP genes, five (CYP2A7, 2S1, 3A5, 4B1, 4V2) were previously associated with patients’ survival and suggested as potential prognosis biomarkers for several types of cancer, including BC—to evaluate tumor progression or aid decisions regarding optimal adjuvant hormonal therapy [23,29,30].