PRKDC and breast cancer: Patient 51 is a 38-year old hormone-positive female breast cancer patient whose tumor presented a gene-copy loss of PTEN, as well as a gene-copy amplification of CCND1, FGFR1, and PRKDC. She received four regimens that were associated with progressive disease (FAC, paclitaxel, capecitabine, and tamoxifen) and one (anastrozole and everolimus combined) that led to a partial response lasting 11 months.