ACTB and neoplasm: Twenty-four hours later the upper half of the left tibia (site of intratibial clot induction) was isolated and the number of tumor cells arriving at the site was evaluated using quantitative real time polymerase chain reaction (qPCR) to determine the number of cancer cells, whereby the frequency of a specific sequence found exclusively in the cancer cell line corrected to murine β-actin reflecting the number of murine bone marrow cells was used.