TP53 and Down syndrome: There are also other less-commonly reported hereditary cancer predisposition syndromes (HCPS) that are associated with either high or moderate GC risk, such as hereditary breast and ovarian cancer syndrome (BRCA1/2), Li-Fraumeni syndrome (TP53), Cowden syndrome (PTEN), Ataxia-telangiectasia (ATM), and Bloom syndrome (BLM) [10].