Tumor-free survival curves of individual tumor histotypes showed that hemangiosarcoma-free survival and osteosarcoma-free survival were significantly different between BALB-p53+/− and RGKO-p53+/−mice, whereas lymphoma-free survival did not differ significantly and soft tissue sarcoma-free and mammary carcinoma-free survival almost overlapped, possibly suggesting a (weak) immunological control in long-term tumor development mainly regarding sarcomas (Fig. 6B). This evidence concerns the gene TP53 and osteosarcoma.