TP53 is a tumor suppressor, repair gene and transcriptional regulator, and it is considered the most frequently mutated gene in cancer. Germline mutations in TP53 lead to Li-Fraumeni syndrome and cancer, including early-onset colorectal cancer. Antibodies are used to identify both wild-type and mutant TP53 and its accumulation in various neoplasias, and have strong staining in tumors with mutations that stabilize the protein. TP53 stains positively in breast, lung and endometrial carcinoma, follicular and mantle cell lymphoma, serous ovarian carcinoma, transitional cell carcinoma of the bladder and colorectal adenocarcinoma. TP53 is also often overexpressed in colorectal dysplasia resulting from ulcerative colitis. In normal tissue, TP53 has weak nuclear staining in fractions of cells in most tissues. References: Genome Res. 2017 Oct;27(10):1645-1657, PMID: 28904012; JAMA Oncol. 2015 May;1(2):214-21, PMID: 26086041; Int J Mol Sci. 2017 Jun 16;18(6). pii: E1284, PMID: 28621756