In vitro experiments: NMR spectroscopy and gel electrophoresis show no significant difference between zinc-free and holo-p53 with high concentrations of p53; aggregation assay of zinc-free p53 at physiological p53 concentrations shows decrease in aggregation of unstable zinc-free p53 by HSP90 addition.Colorectal cancer cell lines, also with manipulated expression of p53, PUMA and apoptotic proteins. This evidence concerns the gene BBC3 and colorectal cancer.