LYN and breast cancer: LYN point mutations in breast cancer are rare (0.6%) (https://cancer.sanger.ac.uk/cosmic), but have been associated with anti-estrogen resistance in a subset of ER+ tumors (Schwarz et al., 2014); only 6%–10% of breast cancers show LYN amplification (http://www.cbioportal.org/index.do; https://cancer.sanger.ac.uk/cosmic).