TP53 and small cell lung carcinoma: P53 is a crucial protein that regulates the cell cycle and acts as a tumor suppressor.205 Studies have shown that approximately half of all human cancers, including serous ovarian cancer, lung squamous cell cancer, lung small cell cancer, triple-negative breast cancer, and squamous esophageal cancer, have alterations in the p53 gene, resulting in a loss of p53 function or decreased p53 expression.206–208 As a tumor suppressor TFs closely linked to PPIs, p53 plays a critical role in regulating gene expression, promoting tumor cell cycle arrest, apoptosis, and DNA repair.