Because HPV oncogenes, like SV40LT, are capable of efficiently transforming infected cells and blocking the p53 pathway, among other effects, we tested whether fibroblasts cultured with apoptotic cells were able to grow with anchorage independence by measuring their ability to form colonies in a soft agar assay, as observed with the HeLa, Ca Ski and C-33 A cancer cells (figure 2A, upper line). The gene discussed is TP53; the disease is cancer.