TP53 and infection: To study the effects of mutant p53 on the extra-nuclear, mitochondrial functions of wt p53, parental HCT116 cells (expressing wt p53) were infected, in a first set of experiments and at a multiplicity of infection of <1 colony forming unit per cell, with retroviral vectors expressing either no transgene, or mutants 175H or 273H with a C-terminal 26 amino acid residue truncation (175ΔC and 273ΔC).