TP53 and head and neck cancer: We used cancer cell lines with the following alterations in p53 activity: (1) HeLa and siHA cervical cancer cells that degraded wild type p53 by expression of the viral oncogene E6;(2) C33a cervical cancer cells that overexpressed a mutant p53R273C protein; (3) MCF7 breast cancer cells possessing a wild type p53; (4) HCT116 (wtHCT116) colon cancer cells possessing a wild type p53; (5) HCT116 (muttHCT116) cells with a homozygous p53 deletion caused by Crispr gene editing and (6) SQ20B head and neck cancer cells expressing a mutant p53.