To determine the function of p53 in collective cell motility, we used both gain and loss of p53 function in colorectal and bladder carcinoma cell lines: stable wild type (p53+/+) and stable p53 null (p53-/-) HCT 116 and Tet-off inducible EJ cell line (Methods). Here, TP53 is linked to urinary bladder carcinoma.