TP53 and osteosarcoma: TP53 mutations are associated with CIN and human osteosarcomas have genome-wide DNA instability.34 Osteosarcoma cells isolated from TP53 heterozygous pig 47 and TP53 homozygous knockout pig 242 were checked for mitotic abnormalities, as were the p53-deficient MSC clones (MSC-P, MSC-PK), cell clones with activated TP53-R167H mutation (MSC-PKC, MSC-PKCM) and tumour-derived poSARCO cells.