A complex of A20 and p53. Tissue protein was extracted from normal colon mucosa (control), colon cancer tissue (Cca) and colon polyp epithelium (polyp). The extracts were immune precipitated (IP) by anti-p53 Ab (A, C) or anti-A20 Ab (B, D), and immune blotted (IB) with anti-p53 Ab (A, D) or anti-A20 Ab (B, C). The immune blots indicate a complex of A20/p53 at 143 kDa. Iso pc Ab: The extracts from Cca and polyp were mixed and were precipitated by isotype IgG using as a negative control; the isotype antibody of anti-P53 was used in the experiments of panel A; the isotype antibody of anti-A20 was used in the experiments of panel B. The data represent 3 separate experiments.