MLH1 and breast cancer: In a systematic review of the genetic landscape of breast cancer brain metastases, several genes involved in DNA damage repair were among the 22 most frequently altered genes in brain metastases, including BRCA1, BRCA2, MLH1, ATR, ATM, and CHEK2 whereas these genes were not among the most altered genes cataloged in extracranial distant recurrences33–35.