TP53 and neoplasm: CDKN1A acts as a tumor suppressor via G1 cell cycle arrest, leading to growth arrest, senescence or apoptosis, but CDKN1A inhibits apoptosis and promotes cell proliferation in p53-deficient tumors [[103], [104], [105]]; the HEC-1A as well as the Ishikawa cell lines were found to be TP53- as well as p53-positive [[106], [107], [108], [109]].