We used flow cytometry to isolate GFP(+) and Tom(+) BC and LEC from prostates of 52-week-old Pb-Cre;Cdk12f/f;mT/mG mice (Figure S2B) and observed the expected reduction of Cdk12 transcript in GFP(+) cells (Figure S2C). This evidence concerns the gene PRPF6 and breast cancer.