CYP2A7 and ovarian serous tumor: Examining published data from The Cancer Genome Atlas showed that ~40% of high-grade serous ovarian tumors, including 6% BRCA1 pathogenic variant carriers, exhibited somatic hemizygous deletions overlapping CYP2A7. 32 Moreover, these deletions correlated with a reduced expression level compared with copy neutral CY2A7 (Supplementary Figure S5).