CDKN1B and neoplasm: Surprisingly, although p27 levels were higher in the homogenized femora of mice inoculated with tumor cells that express PTHrP lacking the NLS and C-terminal domain, there was significantly elevated osteolytic bone destruction (Fig. 5B-D) and tumor burden (Fig. 5E) in the contralateral limb, as measured by flow cytometric analysis of CD298 + tumor cells, a validated marker for human tumor cells in the bone marrow [45].