{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Ataxia telangiectasia mutated (ATM) protein is a serine/threonine kinase that belongs to the family of phosphatidylinositol-3 kinase (PI3K)- related protein kinases. ATM is a key checkpoint protein of the DNA damage response pathway. When DNA double-strand breaks occur, ATM activates different cascades, resulting in activation of cell cycle checkpoints, cell cycle arrests, and apoptosis."}]},{"type":"paragraph","children":[{"type":"text","value":"Mutations in the ATM gene lead to an increased risk of several cancer types, which include Leukemias, Lymphomas, Colorectal Cancer, Pancreatic Cancer and Adenocarcinoma of the Stomach. Studies show that Gastric Cancer tissues were found to be ATM-negative by IHC staining, indicating that ATM can be used as a biomarker. It has also been found that low expression of the ATM protein contributes to more aggressive progression and poor clinical outcome of Breast Cancer. Results of another study indicate loss of ATM protein expression is associated with development of Lung Cancer."}]}]}