Because Pim1 has been found to regulate the actin cytoskeleton in prostate cancer cells, thus promoting their invasive motility44, and the Pim1−/− BMMs were poorly resorptive (Fig. 2b, c), we hypothesized that Pim1 regulates osteoclast function by controlling the actin cytoskeleton reorganization. This evidence concerns the gene PIM1 and Familial prostate cancer.