Statistically, in all the diagnosed cases, 90% of BC is due to an aberrant mutation in various genes and 5-10% is due to the dysfunctional genes inherited from parents [3].Around 2,948 genes have been reported to be involved directly or indirectly in breast cancer development, in which 466 plays a crucial role in the development of cancer [18].The genes, which are potentially responsible for breast cancer, are BRCA1, BRCA2, PTEN, ATM, BARD1, BRIP1, CHEK2, PALB2, RAD50, etc. In general, gene expression profiling has asignificant role in the early detection of breast cancer. Here, ATM is linked to breast cancer.